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<?xml-stylesheet type="text/xsl" href="https://communities.bentley.com/cfs-file/__key/system/syndication/rss.xsl" media="screen"?><rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/"><channel><title>RCDC-Footing</title><link>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing</link><description /><dc:language>en-US</dc:language><generator>Telligent Community 12</generator><item><title>RCDC-Footing</title><link>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing</link><pubDate>Mon, 21 Aug 2023 12:10:58 GMT</pubDate><guid isPermaLink="false">6dad98f5-dbc9-4c4d-a9ba-e9da8dc6aa8e:b8d0de3a-5bef-41b5-b7fb-e6dff09549e5</guid><dc:creator>Ranjana Shinde</dc:creator><comments>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing#comments</comments><description>Current Revision posted to RAM | STAAD | ADINA Wiki by Ranjana Shinde on 8/21/2023 12:10:58 PM&lt;br /&gt;
&lt;h1&gt;&lt;b&gt;&lt;img alt=" " src="/resized-image/__size/189x60/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1647322192004v2.png" /&gt;&lt;/b&gt;&lt;/h1&gt;
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&lt;td style="text-align:right;"&gt;&lt;span style="font-size:medium;"&gt;&lt;b&gt;Applies To&lt;/b&gt;&lt;/span&gt;&lt;/td&gt;
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&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Product(s):&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;STAAD Advanced Concrete Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Version(s):&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Connect Edition&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Environment:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Area:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Concrete Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Subarea:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Footing Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Original Author:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Bentley Technical Support Group&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;/tbody&gt;
&lt;/table&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;&lt;/p&gt;
&lt;ol&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[While designing for reinforcement requirement]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[Footing Design with tension in Column]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[Eccentric Footing design in RCDC]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[Footing Design with loss of contact condition in RCDC]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[Base pressure calculation in RCDC]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[How the effective self-weight of the footing is calculated?]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[For calculation of two way (punching) shear, footing self-weight is not added to axial load.]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[As per design, required reinforcement is 1478/1528 sqmm along L/B direction. Provided reinforcement is T12@175 mm which amounts to 1453 sqmm only for 2.25 m width of footing, whereas the calculation report shows Ast provided as 1583sqmm. Please clarify.]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[Please clarify the footing type &amp;ldquo;on raft&amp;rdquo; given in RCDC.]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[How is the volume of trapezoidal footing calculated in RCDC?]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[RCDC Footing minimum reinforcement]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[Trying to Make footing square in RCDC]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[Reaction mismatch between RCDC and STAAD for footing design]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[LOC(Loss Of Contact) for Footing.]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[SLIDING CHECK IS NOT PERFORMING FOR FOOTING.]]&lt;/li&gt;
&lt;/ol&gt;
&lt;p style="padding-left:120px;"&gt;&lt;strong&gt;&lt;em&gt;&amp;nbsp;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;

&lt;div style="font-size: 90%;"&gt;Tags: loss of contact, footing, RCDC, Eccentric Footing Design&lt;/div&gt;
</description></item><item><title>RCDC-Footing</title><link>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing/revision/24</link><pubDate>Mon, 21 Aug 2023 11:38:31 GMT</pubDate><guid isPermaLink="false">6dad98f5-dbc9-4c4d-a9ba-e9da8dc6aa8e:b8d0de3a-5bef-41b5-b7fb-e6dff09549e5</guid><dc:creator>Ranjana Shinde</dc:creator><comments>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing#comments</comments><description>Revision 24 posted to RAM | STAAD | ADINA Wiki by Ranjana Shinde on 8/21/2023 11:38:31 AM&lt;br /&gt;
&lt;h1&gt;&lt;b&gt;&lt;img alt=" " src="/resized-image/__size/189x60/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1647322192004v2.png" /&gt;&lt;/b&gt;&lt;/h1&gt;
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&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;span style="font-size:medium;"&gt;&lt;b&gt;Applies To&lt;/b&gt;&lt;/span&gt;&lt;/td&gt;
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&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
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&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Product(s):&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;STAAD Advanced Concrete Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Version(s):&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Connect Edition&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Environment:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Area:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Concrete Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Subarea:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Footing Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Original Author:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Bentley Technical Support Group&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
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&lt;/tr&gt;
&lt;/tbody&gt;
&lt;/table&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;&lt;/p&gt;
&lt;ol&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[While designing for reinforcement requirement]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[Footing Design with tension in Column]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[Eccentric Footing design in RCDC]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[Footing Design with loss of contact condition in RCDC]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[Base pressure calculation in RCDC]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[How the effective self-weight of the footing is calculated?]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[For calculation of two way (punching) shear, footing self-weight is not added to axial load.]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[As per design, required reinforcement is 1478/1528 sqmm along L/B direction. Provided reinforcement is T12@175 mm which amounts to 1453 sqmm only for 2.25 m width of footing, whereas the calculation report shows Ast provided as 1583sqmm. Please clarify.]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[Please clarify the footing type &amp;ldquo;on raft&amp;rdquo; given in RCDC.]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[How is the volume of trapezoidal footing calculated in RCDC?]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[RCDC Footing minimum reinforcement]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[Trying to Make footing square in RCDC]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[Reaction mismatch between RCDC and STAAD for footing design]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[LOC(Loss Of Contact) for Footing.]]&lt;/li&gt;
&lt;/ol&gt;
&lt;p style="padding-left:120px;"&gt;&lt;strong&gt;&lt;em&gt;&amp;nbsp;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;

&lt;div style="font-size: 90%;"&gt;Tags: loss of contact, footing, RCDC, Eccentric Footing Design&lt;/div&gt;
</description></item><item><title>RCDC-Footing</title><link>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing/revision/23</link><pubDate>Mon, 15 May 2023 08:49:14 GMT</pubDate><guid isPermaLink="false">6dad98f5-dbc9-4c4d-a9ba-e9da8dc6aa8e:b8d0de3a-5bef-41b5-b7fb-e6dff09549e5</guid><dc:creator>Abhisek M</dc:creator><comments>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing#comments</comments><description>Revision 23 posted to RAM | STAAD | ADINA Wiki by Abhisek M on 5/15/2023 8:49:14 AM&lt;br /&gt;
&lt;h1&gt;&lt;b&gt;&lt;img alt=" " src="/resized-image/__size/189x60/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1647322192004v2.png" /&gt;&lt;/b&gt;&lt;/h1&gt;
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&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
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&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;span style="font-size:medium;"&gt;&lt;b&gt;Applies To&lt;/b&gt;&lt;/span&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
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&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
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&lt;/tr&gt;
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&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Product(s):&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;STAAD Advanced Concrete Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Version(s):&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Connect Edition&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Environment:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Area:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Concrete Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Subarea:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Footing Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Original Author:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Bentley Technical Support Group&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;/tbody&gt;
&lt;/table&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;&lt;/p&gt;
&lt;ol&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[While designing for reinforcement requirement]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[Footing Design with tension in Column]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[Eccentric Footing design in RCDC]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[Footing Design with loss of contact condition in RCDC]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[Base pressure calculation in RCDC]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[How the effective self-weight of the footing is calculated?]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[For calculation of two way (punching) shear, footing self-weight is not added to axial load.]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[As per design, required reinforcement is 1478/1528 sqmm along L/B direction. Provided reinforcement is T12@175 mm which amounts to 1453 sqmm only for 2.25 m width of footing, whereas the calculation report shows Ast provided as 1583sqmm. Please clarify.]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[Please clarify the footing type &amp;ldquo;on raft&amp;rdquo; given in RCDC.]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[How is the volume of trapezoidal footing calculated in RCDC?]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[RCDC Footing minimum reinforcement]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[Trying to Make footing square in RCDC]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[Reaction mismatch between RCDC and STAAD for footing design]]&lt;/li&gt;
&lt;/ol&gt;
&lt;p style="padding-left:120px;"&gt;&lt;strong&gt;&lt;em&gt;&amp;nbsp;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;

&lt;div style="font-size: 90%;"&gt;Tags: loss of contact, footing, RCDC, Eccentric Footing Design&lt;/div&gt;
</description></item><item><title>RCDC-Footing</title><link>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing/revision/22</link><pubDate>Wed, 18 Jan 2023 06:48:13 GMT</pubDate><guid isPermaLink="false">6dad98f5-dbc9-4c4d-a9ba-e9da8dc6aa8e:b8d0de3a-5bef-41b5-b7fb-e6dff09549e5</guid><dc:creator>Nidhi Valia</dc:creator><comments>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing#comments</comments><description>Revision 22 posted to RAM | STAAD | ADINA Wiki by Nidhi Valia on 1/18/2023 6:48:13 AM&lt;br /&gt;
&lt;h1&gt;&lt;b&gt;&lt;img alt=" " src="/resized-image/__size/189x60/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1647322192004v2.png" /&gt;&lt;/b&gt;&lt;/h1&gt;
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&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
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&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;span style="font-size:medium;"&gt;&lt;b&gt;Applies To&lt;/b&gt;&lt;/span&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
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&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
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&lt;td&gt;&lt;/td&gt;
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&lt;/tr&gt;
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&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Product(s):&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;STAAD Advanced Concrete Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Version(s):&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Connect Edition&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Environment:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Area:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Concrete Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Subarea:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Footing Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Original Author:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Bentley Technical Support Group&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;/tbody&gt;
&lt;/table&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;&lt;/p&gt;
&lt;ol&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[While designing for reinforcement requirement]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[Footing Design with tension in Column]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[Eccentric Footing design in RCDC]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[Footing Design with loss of contact condition in RCDC]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[Base pressure calculation in RCDC]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[How the effective self-weight of the footing is calculated?]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[For calculation of two way (punching) shear, footing self-weight is not added to axial load.]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[As per design, required reinforcement is 1478/1528 sqmm along L/B direction. Provided reinforcement is T12@175 mm which amounts to 1453 sqmm only for 2.25 m width of footing, whereas the calculation report shows Ast provided as 1583sqmm. Please clarify.]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[Please clarify the footing type &amp;ldquo;on raft&amp;rdquo; given in RCDC.]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[How is the volume of trapezoidal footing calculated in RCDC?]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[RCDC Footing minimum reinforcement]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[Trying to Make footing square in RCDC]]&lt;/li&gt;
&lt;/ol&gt;
&lt;p style="padding-left:90px;"&gt;&lt;br /&gt;&lt;span&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:120px;"&gt;&lt;strong&gt;&lt;em&gt;&amp;nbsp;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;

&lt;div style="font-size: 90%;"&gt;Tags: loss of contact, footing, RCDC, Eccentric Footing Design&lt;/div&gt;
</description></item><item><title>RCDC-Footing</title><link>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing/revision/21</link><pubDate>Fri, 22 Apr 2022 10:17:20 GMT</pubDate><guid isPermaLink="false">6dad98f5-dbc9-4c4d-a9ba-e9da8dc6aa8e:b8d0de3a-5bef-41b5-b7fb-e6dff09549e5</guid><dc:creator>Abhisek M</dc:creator><comments>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing#comments</comments><description>Revision 21 posted to RAM | STAAD | ADINA Wiki by Abhisek M on 4/22/2022 10:17:20 AM&lt;br /&gt;
&lt;h1&gt;&lt;b&gt;&lt;img alt=" " src="/resized-image/__size/189x60/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1647322192004v2.png" /&gt;&lt;/b&gt;&lt;/h1&gt;
&lt;table style="background-color:#dce5f0;border:0px solid #dce5f0;width:500px;" border="0"&gt;
&lt;tbody&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
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&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
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&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;span style="font-size:medium;"&gt;&lt;b&gt;Applies To&lt;/b&gt;&lt;/span&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
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&lt;/tr&gt;
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&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Product(s):&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;STAAD Advanced Concrete Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Version(s):&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Connect Edition&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Environment:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Area:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Concrete Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Subarea:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Footing Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Original Author:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Bentley Technical Support Group&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;/tbody&gt;
&lt;/table&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;&lt;/p&gt;
&lt;ol&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[While designing for reinforcement requirement]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[Footing Design with tension in Column]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[Eccentric Footing design in RCDC]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[Footing Design with loss of contact condition in RCDC]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[Base pressure calculation in RCDC]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[How the effective self-weight of the footing is calculated?]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[For calculation of two way (punching) shear, footing self-weight is not added to axial load.]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[As per design, required reinforcement is 1478/1528 sqmm along L/B direction. Provided reinforcement is T12@175 mm which amounts to 1453 sqmm only for 2.25 m width of footing, whereas the calculation report shows Ast provided as 1583sqmm. Please clarify.]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[Please clarify the footing type &amp;ldquo;on raft&amp;rdquo; given in RCDC.]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[How is the volume of trapezoidal footing calculated in RCDC?]]&lt;/li&gt;
&lt;li style="margin:0in 0in 0pt;"&gt;[[RCDC Footing minimum reinforcement]]&lt;/li&gt;
&lt;/ol&gt;
&lt;p style="padding-left:90px;"&gt;&lt;br /&gt;&lt;span&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:120px;"&gt;&lt;strong&gt;&lt;em&gt;&amp;nbsp;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;

&lt;div style="font-size: 90%;"&gt;Tags: loss of contact, footing, RCDC, Eccentric Footing Design&lt;/div&gt;
</description></item><item><title>RCDC-Footing</title><link>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing/revision/20</link><pubDate>Fri, 22 Apr 2022 08:17:53 GMT</pubDate><guid isPermaLink="false">6dad98f5-dbc9-4c4d-a9ba-e9da8dc6aa8e:b8d0de3a-5bef-41b5-b7fb-e6dff09549e5</guid><dc:creator>Suvadeep Acharjee</dc:creator><comments>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing#comments</comments><description>Revision 20 posted to RAM | STAAD | ADINA Wiki by Suvadeep Acharjee on 4/22/2022 8:17:53 AM&lt;br /&gt;
&lt;h1&gt;&lt;b&gt;&lt;img alt=" " src="/resized-image/__size/189x60/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1647322192004v2.png" /&gt;&lt;/b&gt;&lt;/h1&gt;
&lt;table style="background-color:#dce5f0;border:0px solid #dce5f0;width:500px;" border="0"&gt;
&lt;tbody&gt;
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&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
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&lt;/tr&gt;
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&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;span style="font-size:medium;"&gt;&lt;b&gt;Applies To&lt;/b&gt;&lt;/span&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Product(s):&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;STAAD Advanced Concrete Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Version(s):&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Connect Edition&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Environment:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Area:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Concrete Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Subarea:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Footing Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Original Author:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Bentley Technical Support Group&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;/tbody&gt;
&lt;/table&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[While designing for reinforcement requirement]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[Footing Design with tension in Column]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[Eccentric Footing design in RCDC]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[Footing Design with loss of contact condition in RCDC]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[Base pressure calculation in RCDC]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[How the effective self-weight of the footing is calculated?]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[For calculation of two way (punching) shear, footing self-weight is not added to axial load.]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[As per design, required reinforcement is 1478/1528 sqmm along L/B direction. Provided reinforcement is T12@175 mm which amounts to 1453 sqmm only for 2.25 m width of footing, whereas the calculation report shows Ast provided as 1583sqmm. Please clarify.]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[Please clarify the footing type &amp;ldquo;on raft&amp;rdquo; given in RCDC.]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[How is the volume of trapezoidal footing calculated in RCDC?]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[RCDC Footing minimum reinforcement]]&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;1. How the effective self-weight of the footing is calculated?&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;Effective self-weight of footing is calculated as additional load of footing volume with respect to difference in density of concrete and soil. For more information refer &amp;ldquo;Technical discussion&amp;rdquo; of footing from help Content.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;2. For calculation of two way (punching) shear, footing self-weight is not added to axial load.&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;Concept of Footing punching shear criteria is column punches in the footing. Load from the column punches the column in footing. Self-weight of footing, overburden load do not participate in punching of column as it is a uniformly distributed load, thus it is not considered in design. For more information refer &amp;ldquo;Technical discussion&amp;rdquo; of footing from help Content.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;3. As per design, required reinforcement is 1478/1528 sqmm along L/B direction. Provided reinforcement is T12@175 mm which amounts to 1453 sqmm only for 2.25 m width of footing, whereas the calculation report shows Ast provided as 1583sqmm. Please clarify&lt;/strong&gt;.
&lt;ul&gt;
&lt;li&gt;Width = 2250 mm Ast required = 1478 sqmm Reinforcement provided = T12@175 mm In RCDC the number of bars required are calculated and spacing is calculated. While presenting the spacing rounded to 5 mm. In this example, number of bars as per spacing would be calculated as below &amp;ndash; (2250 / 175 = 12.86 which is 13 spaces). Hence number of bars would be 14. Thus actual Ast-provided would be (14x113.097 = 1584) 1584 sqmm which is more than required.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;4. Please clarify the footing type &amp;ldquo;on raft&amp;rdquo; given in RCDC&lt;/strong&gt;.
&lt;ul&gt;
&lt;li&gt;RCDC designs the isolated footings. The purpose of this options is to maintain the same thickness of first step for all footings if all footing are connected by common raft. This type of footing mostly use in the basement structures. The concept of this type of footing is similar to stepped footing.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;5. How is the volume of trapezoidal footing calculated in RCDC?&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;RCDC calculates the weight of trapezoidal footing as per following formulations, Self-wt. of footing Volume of footing = ((L*B*D) + ((((L*B) + (Lt*Bt))/2)*(D-d))/1000^3 Where, L= Length of footing B= Width of footing D= Depth of footing Lt= Length of footing top Bt= Width of footing top d= depth of sloping area.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;6.&lt;em&gt;In RCDC, the minimum rebar&amp;rsquo;s in Bottom are calculation based on effective Depth of the Foundation (Dff),whereas as per Clause 26.5.2.1 the minimum %Pt&amp;nbsp; is 0.12 of the Gross cross section area. Ast (minimum) as per IS456-200 Clause 26.5.2.1 is 0.12% of the Gross Cross section area.&lt;em&gt;Therefore,&amp;nbsp; for&amp;nbsp; F4 1800 x 1800 x 500 thk. : Ast mini = (0.12/100) x 500 x 1800 = 1080 Sqmm. &lt;em&gt;RCDC Calculations. Area calculation based on Deff. { (0.12/100) x 411 x 1800 = 887.76 Sqmm }. &lt;em&gt;Actually we end up providing less %Pt than required. &amp;lt; 1080 sqmm actual requirement vs 888 sqmm Provided&amp;gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;Please refer below snap extracted from IS 456,&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1598267093444v1.png" /&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Minimum reinforcement is for the total cross section area, thus 0.12% steel is to be provided at top and bottom.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;In your case, top reinforcement is selected and below is the reinforcement given,&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1598267129735v2.png" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;The minimum bottom reinforcement is given as 0.12% and top as 0.06%. Thus In your case, the RCDC will check the total reinforcement to be provided at a given cross section area as 0.12%. here, 0.06% is already provided at top, thus at bottom it will provided as per the 0.12% given by you with deff. Refer below snap of calculation &amp;nbsp;report.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/0410.jpg" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Now, don&amp;rsquo;t select the top reinforcement and maintain the same reinforcement, below is the output&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/3124.jpg" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Reinforcement is provided indirectly as 0.12% with total depth. 0.12 x 500 x 1800/100 = 1080 sqmm.&amp;nbsp; If we take Deff, then 0.141 x 427 x 1800/100 = 1083.72 sqmm. So the final reinforcement required is 1080 sqmm.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Here, the required pt has increased to match with the 0.12% with total D.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;If you want to reduce the Bottom reinforcement, please provide bottom reinforcement as 0.06%&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;br /&gt;&lt;span&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:120px;"&gt;&lt;strong&gt;&lt;em&gt;&amp;nbsp;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;

&lt;div style="font-size: 90%;"&gt;Tags: loss of contact, footing, RCDC, Eccentric Footing Design&lt;/div&gt;
</description></item><item><title>RCDC-Footing</title><link>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing/revision/19</link><pubDate>Fri, 22 Apr 2022 08:13:31 GMT</pubDate><guid isPermaLink="false">6dad98f5-dbc9-4c4d-a9ba-e9da8dc6aa8e:b8d0de3a-5bef-41b5-b7fb-e6dff09549e5</guid><dc:creator>Suvadeep Acharjee</dc:creator><comments>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing#comments</comments><description>Revision 19 posted to RAM | STAAD | ADINA Wiki by Suvadeep Acharjee on 4/22/2022 8:13:31 AM&lt;br /&gt;
&lt;h1&gt;&lt;b&gt;&lt;img alt=" " src="/resized-image/__size/189x60/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1647322192004v2.png" /&gt;&lt;/b&gt;&lt;/h1&gt;
&lt;table style="background-color:#dce5f0;border:0px solid #dce5f0;width:500px;" border="0"&gt;
&lt;tbody&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;span style="font-size:medium;"&gt;&lt;b&gt;Applies To&lt;/b&gt;&lt;/span&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Product(s):&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;STAAD Advanced Concrete Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Version(s):&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Connect Edition&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Environment:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Area:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Concrete Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Subarea:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Footing Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Original Author:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Bentley Technical Support Group&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;/tbody&gt;
&lt;/table&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[While designing for reinforcement requirement]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[Footing Design with tension in Column]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[Eccentric Footing design in RCDC]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[Footing Design with loss of contact condition in RCDC]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[Base pressure calculation in RCDC]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[How the effective self-weight of the footing is calculated?]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[For calculation of two way (punching) shear, footing self-weight is not added to axial load.]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[As per design, required reinforcement is 1478/1528 sqmm along L/B direction. Provided reinforcement is T12@175 mm which amounts to 1453 sqmm only for 2.25 m width of footing, whereas the calculation report shows Ast provided as 1583sqmm. Please clarify.]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[Please clarify the footing type &amp;ldquo;on raft&amp;rdquo; given in RCDC.]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[How is the volume of trapezoidal footing calculated in RCDC?]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[In RCDC, the minimum rebar&amp;rsquo;s in Bottom are calculation based on effective Depth of the Foundation (Dff),whereas as per Clause 26.5.2.1 the minimum %Pt is 0.12 of the Gross cross section area. Ast (minimum) as per IS456-200 Clause 26.5.2.1 is 0.12% of the]]&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;1. How the effective self-weight of the footing is calculated?&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;Effective self-weight of footing is calculated as additional load of footing volume with respect to difference in density of concrete and soil. For more information refer &amp;ldquo;Technical discussion&amp;rdquo; of footing from help Content.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;2. For calculation of two way (punching) shear, footing self-weight is not added to axial load.&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;Concept of Footing punching shear criteria is column punches in the footing. Load from the column punches the column in footing. Self-weight of footing, overburden load do not participate in punching of column as it is a uniformly distributed load, thus it is not considered in design. For more information refer &amp;ldquo;Technical discussion&amp;rdquo; of footing from help Content.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;3. As per design, required reinforcement is 1478/1528 sqmm along L/B direction. Provided reinforcement is T12@175 mm which amounts to 1453 sqmm only for 2.25 m width of footing, whereas the calculation report shows Ast provided as 1583sqmm. Please clarify&lt;/strong&gt;.
&lt;ul&gt;
&lt;li&gt;Width = 2250 mm Ast required = 1478 sqmm Reinforcement provided = T12@175 mm In RCDC the number of bars required are calculated and spacing is calculated. While presenting the spacing rounded to 5 mm. In this example, number of bars as per spacing would be calculated as below &amp;ndash; (2250 / 175 = 12.86 which is 13 spaces). Hence number of bars would be 14. Thus actual Ast-provided would be (14x113.097 = 1584) 1584 sqmm which is more than required.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;4. Please clarify the footing type &amp;ldquo;on raft&amp;rdquo; given in RCDC&lt;/strong&gt;.
&lt;ul&gt;
&lt;li&gt;RCDC designs the isolated footings. The purpose of this options is to maintain the same thickness of first step for all footings if all footing are connected by common raft. This type of footing mostly use in the basement structures. The concept of this type of footing is similar to stepped footing.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;5. How is the volume of trapezoidal footing calculated in RCDC?&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;RCDC calculates the weight of trapezoidal footing as per following formulations, Self-wt. of footing Volume of footing = ((L*B*D) + ((((L*B) + (Lt*Bt))/2)*(D-d))/1000^3 Where, L= Length of footing B= Width of footing D= Depth of footing Lt= Length of footing top Bt= Width of footing top d= depth of sloping area.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;6.&lt;em&gt;In RCDC, the minimum rebar&amp;rsquo;s in Bottom are calculation based on effective Depth of the Foundation (Dff),whereas as per Clause 26.5.2.1 the minimum %Pt&amp;nbsp; is 0.12 of the Gross cross section area. Ast (minimum) as per IS456-200 Clause 26.5.2.1 is 0.12% of the Gross Cross section area.&lt;em&gt;Therefore,&amp;nbsp; for&amp;nbsp; F4 1800 x 1800 x 500 thk. : Ast mini = (0.12/100) x 500 x 1800 = 1080 Sqmm. &lt;em&gt;RCDC Calculations. Area calculation based on Deff. { (0.12/100) x 411 x 1800 = 887.76 Sqmm }. &lt;em&gt;Actually we end up providing less %Pt than required. &amp;lt; 1080 sqmm actual requirement vs 888 sqmm Provided&amp;gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;Please refer below snap extracted from IS 456,&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1598267093444v1.png" /&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Minimum reinforcement is for the total cross section area, thus 0.12% steel is to be provided at top and bottom.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;In your case, top reinforcement is selected and below is the reinforcement given,&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1598267129735v2.png" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;The minimum bottom reinforcement is given as 0.12% and top as 0.06%. Thus In your case, the RCDC will check the total reinforcement to be provided at a given cross section area as 0.12%. here, 0.06% is already provided at top, thus at bottom it will provided as per the 0.12% given by you with deff. Refer below snap of calculation &amp;nbsp;report.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/0410.jpg" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Now, don&amp;rsquo;t select the top reinforcement and maintain the same reinforcement, below is the output&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/3124.jpg" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Reinforcement is provided indirectly as 0.12% with total depth. 0.12 x 500 x 1800/100 = 1080 sqmm.&amp;nbsp; If we take Deff, then 0.141 x 427 x 1800/100 = 1083.72 sqmm. So the final reinforcement required is 1080 sqmm.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Here, the required pt has increased to match with the 0.12% with total D.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;If you want to reduce the Bottom reinforcement, please provide bottom reinforcement as 0.06%&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;br /&gt;&lt;span&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:120px;"&gt;&lt;strong&gt;&lt;em&gt;&amp;nbsp;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;

&lt;div style="font-size: 90%;"&gt;Tags: loss of contact, footing, RCDC, Eccentric Footing Design&lt;/div&gt;
</description></item><item><title>RCDC-Footing</title><link>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing/revision/18</link><pubDate>Fri, 22 Apr 2022 07:44:24 GMT</pubDate><guid isPermaLink="false">6dad98f5-dbc9-4c4d-a9ba-e9da8dc6aa8e:b8d0de3a-5bef-41b5-b7fb-e6dff09549e5</guid><dc:creator>Suvadeep Acharjee</dc:creator><comments>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing#comments</comments><description>Revision 18 posted to RAM | STAAD | ADINA Wiki by Suvadeep Acharjee on 4/22/2022 7:44:24 AM&lt;br /&gt;
&lt;h1&gt;&lt;b&gt;&lt;img alt=" " src="/resized-image/__size/189x60/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1647322192004v2.png" /&gt;&lt;/b&gt;&lt;/h1&gt;
&lt;table style="background-color:#dce5f0;border:0px solid #dce5f0;width:500px;" border="0"&gt;
&lt;tbody&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;span style="font-size:medium;"&gt;&lt;b&gt;Applies To&lt;/b&gt;&lt;/span&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Product(s):&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;STAAD Advanced Concrete Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Version(s):&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Connect Edition&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Environment:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Area:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Concrete Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Subarea:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Footing Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Original Author:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Bentley Technical Support Group&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;/tbody&gt;
&lt;/table&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[While designing for reinforcement requirement]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[Footing Design with tension in Column]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[Eccentric Footing design in RCDC]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[Footing Design with loss of contact condition in RCDC]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[Base pressure calculation in RCDC]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[How the effective self-weight of the footing is calculated?]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[For calculation of two way (punching) shear, footing self-weight is not added to axial load.]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[As per design, required reinforcement is 1478/1528 sqmm along L/B direction. Provided reinforcement is T12@175 mm which amounts to 1453 sqmm only for 2.25 m width of footing, whereas the calculation report shows Ast provided as 1583sqmm. Please clarify.]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[Please clarify the footing type &amp;ldquo;on raft&amp;rdquo; given in RCDC.]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[How is the volume of trapezoidal footing calculated in RCDC?]]&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;1. How the effective self-weight of the footing is calculated?&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;Effective self-weight of footing is calculated as additional load of footing volume with respect to difference in density of concrete and soil. For more information refer &amp;ldquo;Technical discussion&amp;rdquo; of footing from help Content.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;2. For calculation of two way (punching) shear, footing self-weight is not added to axial load.&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;Concept of Footing punching shear criteria is column punches in the footing. Load from the column punches the column in footing. Self-weight of footing, overburden load do not participate in punching of column as it is a uniformly distributed load, thus it is not considered in design. For more information refer &amp;ldquo;Technical discussion&amp;rdquo; of footing from help Content.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;3. As per design, required reinforcement is 1478/1528 sqmm along L/B direction. Provided reinforcement is T12@175 mm which amounts to 1453 sqmm only for 2.25 m width of footing, whereas the calculation report shows Ast provided as 1583sqmm. Please clarify&lt;/strong&gt;.
&lt;ul&gt;
&lt;li&gt;Width = 2250 mm Ast required = 1478 sqmm Reinforcement provided = T12@175 mm In RCDC the number of bars required are calculated and spacing is calculated. While presenting the spacing rounded to 5 mm. In this example, number of bars as per spacing would be calculated as below &amp;ndash; (2250 / 175 = 12.86 which is 13 spaces). Hence number of bars would be 14. Thus actual Ast-provided would be (14x113.097 = 1584) 1584 sqmm which is more than required.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;4. Please clarify the footing type &amp;ldquo;on raft&amp;rdquo; given in RCDC&lt;/strong&gt;.
&lt;ul&gt;
&lt;li&gt;RCDC designs the isolated footings. The purpose of this options is to maintain the same thickness of first step for all footings if all footing are connected by common raft. This type of footing mostly use in the basement structures. The concept of this type of footing is similar to stepped footing.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;5. How is the volume of trapezoidal footing calculated in RCDC?&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;RCDC calculates the weight of trapezoidal footing as per following formulations, Self-wt. of footing Volume of footing = ((L*B*D) + ((((L*B) + (Lt*Bt))/2)*(D-d))/1000^3 Where, L= Length of footing B= Width of footing D= Depth of footing Lt= Length of footing top Bt= Width of footing top d= depth of sloping area.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;6.&lt;em&gt;In RCDC, the minimum rebar&amp;rsquo;s in Bottom are calculation based on effective Depth of the Foundation (Dff),whereas as per Clause 26.5.2.1 the minimum %Pt&amp;nbsp; is 0.12 of the Gross cross section area. Ast (minimum) as per IS456-200 Clause 26.5.2.1 is 0.12% of the Gross Cross section area.&lt;em&gt;Therefore,&amp;nbsp; for&amp;nbsp; F4 1800 x 1800 x 500 thk. : Ast mini = (0.12/100) x 500 x 1800 = 1080 Sqmm. &lt;em&gt;RCDC Calculations. Area calculation based on Deff. { (0.12/100) x 411 x 1800 = 887.76 Sqmm }. &lt;em&gt;Actually we end up providing less %Pt than required. &amp;lt; 1080 sqmm actual requirement vs 888 sqmm Provided&amp;gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;Please refer below snap extracted from IS 456,&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1598267093444v1.png" /&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Minimum reinforcement is for the total cross section area, thus 0.12% steel is to be provided at top and bottom.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;In your case, top reinforcement is selected and below is the reinforcement given,&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1598267129735v2.png" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;The minimum bottom reinforcement is given as 0.12% and top as 0.06%. Thus In your case, the RCDC will check the total reinforcement to be provided at a given cross section area as 0.12%. here, 0.06% is already provided at top, thus at bottom it will provided as per the 0.12% given by you with deff. Refer below snap of calculation &amp;nbsp;report.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/0410.jpg" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Now, don&amp;rsquo;t select the top reinforcement and maintain the same reinforcement, below is the output&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/3124.jpg" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Reinforcement is provided indirectly as 0.12% with total depth. 0.12 x 500 x 1800/100 = 1080 sqmm.&amp;nbsp; If we take Deff, then 0.141 x 427 x 1800/100 = 1083.72 sqmm. So the final reinforcement required is 1080 sqmm.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Here, the required pt has increased to match with the 0.12% with total D.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;If you want to reduce the Bottom reinforcement, please provide bottom reinforcement as 0.06%&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;br /&gt;&lt;span&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:120px;"&gt;&lt;strong&gt;&lt;em&gt;&amp;nbsp;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;

&lt;div style="font-size: 90%;"&gt;Tags: loss of contact, footing, RCDC, Eccentric Footing Design&lt;/div&gt;
</description></item><item><title>RCDC-Footing</title><link>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing/revision/17</link><pubDate>Fri, 22 Apr 2022 07:38:01 GMT</pubDate><guid isPermaLink="false">6dad98f5-dbc9-4c4d-a9ba-e9da8dc6aa8e:b8d0de3a-5bef-41b5-b7fb-e6dff09549e5</guid><dc:creator>Suvadeep Acharjee</dc:creator><comments>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing#comments</comments><description>Revision 17 posted to RAM | STAAD | ADINA Wiki by Suvadeep Acharjee on 4/22/2022 7:38:01 AM&lt;br /&gt;
&lt;h1&gt;&lt;b&gt;&lt;img alt=" " src="/resized-image/__size/189x60/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1647322192004v2.png" /&gt;&lt;/b&gt;&lt;/h1&gt;
&lt;table style="background-color:#dce5f0;border:0px solid #dce5f0;width:500px;" border="0"&gt;
&lt;tbody&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;span style="font-size:medium;"&gt;&lt;b&gt;Applies To&lt;/b&gt;&lt;/span&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Product(s):&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;STAAD Advanced Concrete Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Version(s):&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Connect Edition&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Environment:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Area:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Concrete Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Subarea:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Footing Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Original Author:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Bentley Technical Support Group&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;/tbody&gt;
&lt;/table&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[While designing for reinforcement requirement]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[Footing Design with tension in Column]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[Eccentric Footing design in RCDC]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[Footing Design with loss of contact condition in RCDC]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[Base pressure calculation in RCDC]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[How the effective self-weight of the footing is calculated?]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[For calculation of two way (punching) shear, footing self-weight is not added to axial load.]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[As per design, required reinforcement is 1478/1528 sqmm along L/B direction. Provided reinforcement is T12@175 mm which amounts to 1453 sqmm only for 2.25 m width of footing, whereas the calculation report shows Ast provided as 1583sqmm. Please clarify.]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[Please clarify the footing type &amp;ldquo;on raft&amp;rdquo; given in RCDC.]]&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;1. How the effective self-weight of the footing is calculated?&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;Effective self-weight of footing is calculated as additional load of footing volume with respect to difference in density of concrete and soil. For more information refer &amp;ldquo;Technical discussion&amp;rdquo; of footing from help Content.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;2. For calculation of two way (punching) shear, footing self-weight is not added to axial load.&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;Concept of Footing punching shear criteria is column punches in the footing. Load from the column punches the column in footing. Self-weight of footing, overburden load do not participate in punching of column as it is a uniformly distributed load, thus it is not considered in design. For more information refer &amp;ldquo;Technical discussion&amp;rdquo; of footing from help Content.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;3. As per design, required reinforcement is 1478/1528 sqmm along L/B direction. Provided reinforcement is T12@175 mm which amounts to 1453 sqmm only for 2.25 m width of footing, whereas the calculation report shows Ast provided as 1583sqmm. Please clarify&lt;/strong&gt;.
&lt;ul&gt;
&lt;li&gt;Width = 2250 mm Ast required = 1478 sqmm Reinforcement provided = T12@175 mm In RCDC the number of bars required are calculated and spacing is calculated. While presenting the spacing rounded to 5 mm. In this example, number of bars as per spacing would be calculated as below &amp;ndash; (2250 / 175 = 12.86 which is 13 spaces). Hence number of bars would be 14. Thus actual Ast-provided would be (14x113.097 = 1584) 1584 sqmm which is more than required.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;4. Please clarify the footing type &amp;ldquo;on raft&amp;rdquo; given in RCDC&lt;/strong&gt;.
&lt;ul&gt;
&lt;li&gt;RCDC designs the isolated footings. The purpose of this options is to maintain the same thickness of first step for all footings if all footing are connected by common raft. This type of footing mostly use in the basement structures. The concept of this type of footing is similar to stepped footing.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;5. How is the volume of trapezoidal footing calculated in RCDC?&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;RCDC calculates the weight of trapezoidal footing as per following formulations, Self-wt. of footing Volume of footing = ((L*B*D) + ((((L*B) + (Lt*Bt))/2)*(D-d))/1000^3 Where, L= Length of footing B= Width of footing D= Depth of footing Lt= Length of footing top Bt= Width of footing top d= depth of sloping area.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;6.&lt;em&gt;In RCDC, the minimum rebar&amp;rsquo;s in Bottom are calculation based on effective Depth of the Foundation (Dff),whereas as per Clause 26.5.2.1 the minimum %Pt&amp;nbsp; is 0.12 of the Gross cross section area. Ast (minimum) as per IS456-200 Clause 26.5.2.1 is 0.12% of the Gross Cross section area.&lt;em&gt;Therefore,&amp;nbsp; for&amp;nbsp; F4 1800 x 1800 x 500 thk. : Ast mini = (0.12/100) x 500 x 1800 = 1080 Sqmm. &lt;em&gt;RCDC Calculations. Area calculation based on Deff. { (0.12/100) x 411 x 1800 = 887.76 Sqmm }. &lt;em&gt;Actually we end up providing less %Pt than required. &amp;lt; 1080 sqmm actual requirement vs 888 sqmm Provided&amp;gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;Please refer below snap extracted from IS 456,&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1598267093444v1.png" /&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Minimum reinforcement is for the total cross section area, thus 0.12% steel is to be provided at top and bottom.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;In your case, top reinforcement is selected and below is the reinforcement given,&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1598267129735v2.png" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;The minimum bottom reinforcement is given as 0.12% and top as 0.06%. Thus In your case, the RCDC will check the total reinforcement to be provided at a given cross section area as 0.12%. here, 0.06% is already provided at top, thus at bottom it will provided as per the 0.12% given by you with deff. Refer below snap of calculation &amp;nbsp;report.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/0410.jpg" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Now, don&amp;rsquo;t select the top reinforcement and maintain the same reinforcement, below is the output&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/3124.jpg" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Reinforcement is provided indirectly as 0.12% with total depth. 0.12 x 500 x 1800/100 = 1080 sqmm.&amp;nbsp; If we take Deff, then 0.141 x 427 x 1800/100 = 1083.72 sqmm. So the final reinforcement required is 1080 sqmm.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Here, the required pt has increased to match with the 0.12% with total D.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;If you want to reduce the Bottom reinforcement, please provide bottom reinforcement as 0.06%&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;br /&gt;&lt;span&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:120px;"&gt;&lt;strong&gt;&lt;em&gt;&amp;nbsp;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;

&lt;div style="font-size: 90%;"&gt;Tags: loss of contact, footing, RCDC, Eccentric Footing Design&lt;/div&gt;
</description></item><item><title>RCDC-Footing</title><link>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing/revision/16</link><pubDate>Fri, 22 Apr 2022 06:32:59 GMT</pubDate><guid isPermaLink="false">6dad98f5-dbc9-4c4d-a9ba-e9da8dc6aa8e:b8d0de3a-5bef-41b5-b7fb-e6dff09549e5</guid><dc:creator>Suvadeep Acharjee</dc:creator><comments>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing#comments</comments><description>Revision 16 posted to RAM | STAAD | ADINA Wiki by Suvadeep Acharjee on 4/22/2022 6:32:59 AM&lt;br /&gt;
&lt;h1&gt;&lt;b&gt;&lt;img alt=" " src="/resized-image/__size/189x60/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1647322192004v2.png" /&gt;&lt;/b&gt;&lt;/h1&gt;
&lt;table style="background-color:#dce5f0;border:0px solid #dce5f0;width:500px;" border="0"&gt;
&lt;tbody&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;span style="font-size:medium;"&gt;&lt;b&gt;Applies To&lt;/b&gt;&lt;/span&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Product(s):&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;STAAD Advanced Concrete Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Version(s):&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Connect Edition&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Environment:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Area:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Concrete Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Subarea:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Footing Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Original Author:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Bentley Technical Support Group&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;/tbody&gt;
&lt;/table&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[While designing for reinforcement requirement]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[Footing Design with tension in Column]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[Eccentric Footing design in RCDC]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[Footing Design with loss of contact condition in RCDC]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[Base pressure calculation in RCDC]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[How the effective self-weight of the footing is calculated?]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[For calculation of two way (punching) shear, footing self-weight is not added to axial load.]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[As per design, required reinforcement is 1478/1528 sqmm along L/B direction. Provided reinforcement is T12@175 mm which amounts to 1453 sqmm only for 2.25 m width of footing, whereas the calculation report shows Ast provided as 1583sqmm. Please clarify.]]&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;1. How the effective self-weight of the footing is calculated?&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;Effective self-weight of footing is calculated as additional load of footing volume with respect to difference in density of concrete and soil. For more information refer &amp;ldquo;Technical discussion&amp;rdquo; of footing from help Content.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;2. For calculation of two way (punching) shear, footing self-weight is not added to axial load.&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;Concept of Footing punching shear criteria is column punches in the footing. Load from the column punches the column in footing. Self-weight of footing, overburden load do not participate in punching of column as it is a uniformly distributed load, thus it is not considered in design. For more information refer &amp;ldquo;Technical discussion&amp;rdquo; of footing from help Content.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;3. As per design, required reinforcement is 1478/1528 sqmm along L/B direction. Provided reinforcement is T12@175 mm which amounts to 1453 sqmm only for 2.25 m width of footing, whereas the calculation report shows Ast provided as 1583sqmm. Please clarify&lt;/strong&gt;.
&lt;ul&gt;
&lt;li&gt;Width = 2250 mm Ast required = 1478 sqmm Reinforcement provided = T12@175 mm In RCDC the number of bars required are calculated and spacing is calculated. While presenting the spacing rounded to 5 mm. In this example, number of bars as per spacing would be calculated as below &amp;ndash; (2250 / 175 = 12.86 which is 13 spaces). Hence number of bars would be 14. Thus actual Ast-provided would be (14x113.097 = 1584) 1584 sqmm which is more than required.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;4. Please clarify the footing type &amp;ldquo;on raft&amp;rdquo; given in RCDC&lt;/strong&gt;.
&lt;ul&gt;
&lt;li&gt;RCDC designs the isolated footings. The purpose of this options is to maintain the same thickness of first step for all footings if all footing are connected by common raft. This type of footing mostly use in the basement structures. The concept of this type of footing is similar to stepped footing.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;5. How is the volume of trapezoidal footing calculated in RCDC?&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;RCDC calculates the weight of trapezoidal footing as per following formulations, Self-wt. of footing Volume of footing = ((L*B*D) + ((((L*B) + (Lt*Bt))/2)*(D-d))/1000^3 Where, L= Length of footing B= Width of footing D= Depth of footing Lt= Length of footing top Bt= Width of footing top d= depth of sloping area.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;6.&lt;em&gt;In RCDC, the minimum rebar&amp;rsquo;s in Bottom are calculation based on effective Depth of the Foundation (Dff),whereas as per Clause 26.5.2.1 the minimum %Pt&amp;nbsp; is 0.12 of the Gross cross section area. Ast (minimum) as per IS456-200 Clause 26.5.2.1 is 0.12% of the Gross Cross section area.&lt;em&gt;Therefore,&amp;nbsp; for&amp;nbsp; F4 1800 x 1800 x 500 thk. : Ast mini = (0.12/100) x 500 x 1800 = 1080 Sqmm. &lt;em&gt;RCDC Calculations. Area calculation based on Deff. { (0.12/100) x 411 x 1800 = 887.76 Sqmm }. &lt;em&gt;Actually we end up providing less %Pt than required. &amp;lt; 1080 sqmm actual requirement vs 888 sqmm Provided&amp;gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;Please refer below snap extracted from IS 456,&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1598267093444v1.png" /&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Minimum reinforcement is for the total cross section area, thus 0.12% steel is to be provided at top and bottom.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;In your case, top reinforcement is selected and below is the reinforcement given,&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1598267129735v2.png" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;The minimum bottom reinforcement is given as 0.12% and top as 0.06%. Thus In your case, the RCDC will check the total reinforcement to be provided at a given cross section area as 0.12%. here, 0.06% is already provided at top, thus at bottom it will provided as per the 0.12% given by you with deff. Refer below snap of calculation &amp;nbsp;report.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/0410.jpg" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Now, don&amp;rsquo;t select the top reinforcement and maintain the same reinforcement, below is the output&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/3124.jpg" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Reinforcement is provided indirectly as 0.12% with total depth. 0.12 x 500 x 1800/100 = 1080 sqmm.&amp;nbsp; If we take Deff, then 0.141 x 427 x 1800/100 = 1083.72 sqmm. So the final reinforcement required is 1080 sqmm.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Here, the required pt has increased to match with the 0.12% with total D.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;If you want to reduce the Bottom reinforcement, please provide bottom reinforcement as 0.06%&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;br /&gt;&lt;span&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:120px;"&gt;&lt;strong&gt;&lt;em&gt;&amp;nbsp;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;

&lt;div style="font-size: 90%;"&gt;Tags: loss of contact, footing, RCDC, Eccentric Footing Design&lt;/div&gt;
</description></item><item><title>RCDC-Footing</title><link>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing/revision/15</link><pubDate>Fri, 22 Apr 2022 06:26:13 GMT</pubDate><guid isPermaLink="false">6dad98f5-dbc9-4c4d-a9ba-e9da8dc6aa8e:b8d0de3a-5bef-41b5-b7fb-e6dff09549e5</guid><dc:creator>Suvadeep Acharjee</dc:creator><comments>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing#comments</comments><description>Revision 15 posted to RAM | STAAD | ADINA Wiki by Suvadeep Acharjee on 4/22/2022 6:26:13 AM&lt;br /&gt;
&lt;h1&gt;&lt;b&gt;&lt;img alt=" " src="/resized-image/__size/189x60/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1647322192004v2.png" /&gt;&lt;/b&gt;&lt;/h1&gt;
&lt;table style="background-color:#dce5f0;border:0px solid #dce5f0;width:500px;" border="0"&gt;
&lt;tbody&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;span style="font-size:medium;"&gt;&lt;b&gt;Applies To&lt;/b&gt;&lt;/span&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Product(s):&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;STAAD Advanced Concrete Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Version(s):&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Connect Edition&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Environment:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Area:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Concrete Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Subarea:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Footing Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Original Author:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Bentley Technical Support Group&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;/tbody&gt;
&lt;/table&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[While designing for reinforcement requirement]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[Footing Design with tension in Column]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[Eccentric Footing design in RCDC]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[Footing Design with loss of contact condition in RCDC]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[Base pressure calculation in RCDC]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[How the effective self-weight of the footing is calculated?]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[For calculation of two way (punching) shear, footing self-weight is not added to axial load.]]&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;1. How the effective self-weight of the footing is calculated?&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;Effective self-weight of footing is calculated as additional load of footing volume with respect to difference in density of concrete and soil. For more information refer &amp;ldquo;Technical discussion&amp;rdquo; of footing from help Content.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;2. For calculation of two way (punching) shear, footing self-weight is not added to axial load.&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;Concept of Footing punching shear criteria is column punches in the footing. Load from the column punches the column in footing. Self-weight of footing, overburden load do not participate in punching of column as it is a uniformly distributed load, thus it is not considered in design. For more information refer &amp;ldquo;Technical discussion&amp;rdquo; of footing from help Content.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;3. As per design, required reinforcement is 1478/1528 sqmm along L/B direction. Provided reinforcement is T12@175 mm which amounts to 1453 sqmm only for 2.25 m width of footing, whereas the calculation report shows Ast provided as 1583sqmm. Please clarify&lt;/strong&gt;.
&lt;ul&gt;
&lt;li&gt;Width = 2250 mm Ast required = 1478 sqmm Reinforcement provided = T12@175 mm In RCDC the number of bars required are calculated and spacing is calculated. While presenting the spacing rounded to 5 mm. In this example, number of bars as per spacing would be calculated as below &amp;ndash; (2250 / 175 = 12.86 which is 13 spaces). Hence number of bars would be 14. Thus actual Ast-provided would be (14x113.097 = 1584) 1584 sqmm which is more than required.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;4. Please clarify the footing type &amp;ldquo;on raft&amp;rdquo; given in RCDC&lt;/strong&gt;.
&lt;ul&gt;
&lt;li&gt;RCDC designs the isolated footings. The purpose of this options is to maintain the same thickness of first step for all footings if all footing are connected by common raft. This type of footing mostly use in the basement structures. The concept of this type of footing is similar to stepped footing.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;5. How is the volume of trapezoidal footing calculated in RCDC?&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;RCDC calculates the weight of trapezoidal footing as per following formulations, Self-wt. of footing Volume of footing = ((L*B*D) + ((((L*B) + (Lt*Bt))/2)*(D-d))/1000^3 Where, L= Length of footing B= Width of footing D= Depth of footing Lt= Length of footing top Bt= Width of footing top d= depth of sloping area.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;6.&lt;em&gt;In RCDC, the minimum rebar&amp;rsquo;s in Bottom are calculation based on effective Depth of the Foundation (Dff),whereas as per Clause 26.5.2.1 the minimum %Pt&amp;nbsp; is 0.12 of the Gross cross section area. Ast (minimum) as per IS456-200 Clause 26.5.2.1 is 0.12% of the Gross Cross section area.&lt;em&gt;Therefore,&amp;nbsp; for&amp;nbsp; F4 1800 x 1800 x 500 thk. : Ast mini = (0.12/100) x 500 x 1800 = 1080 Sqmm. &lt;em&gt;RCDC Calculations. Area calculation based on Deff. { (0.12/100) x 411 x 1800 = 887.76 Sqmm }. &lt;em&gt;Actually we end up providing less %Pt than required. &amp;lt; 1080 sqmm actual requirement vs 888 sqmm Provided&amp;gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;Please refer below snap extracted from IS 456,&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1598267093444v1.png" /&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Minimum reinforcement is for the total cross section area, thus 0.12% steel is to be provided at top and bottom.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;In your case, top reinforcement is selected and below is the reinforcement given,&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1598267129735v2.png" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;The minimum bottom reinforcement is given as 0.12% and top as 0.06%. Thus In your case, the RCDC will check the total reinforcement to be provided at a given cross section area as 0.12%. here, 0.06% is already provided at top, thus at bottom it will provided as per the 0.12% given by you with deff. Refer below snap of calculation &amp;nbsp;report.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/0410.jpg" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Now, don&amp;rsquo;t select the top reinforcement and maintain the same reinforcement, below is the output&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/3124.jpg" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Reinforcement is provided indirectly as 0.12% with total depth. 0.12 x 500 x 1800/100 = 1080 sqmm.&amp;nbsp; If we take Deff, then 0.141 x 427 x 1800/100 = 1083.72 sqmm. So the final reinforcement required is 1080 sqmm.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Here, the required pt has increased to match with the 0.12% with total D.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;If you want to reduce the Bottom reinforcement, please provide bottom reinforcement as 0.06%&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;br /&gt;&lt;span&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:120px;"&gt;&lt;strong&gt;&lt;em&gt;&amp;nbsp;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;

&lt;div style="font-size: 90%;"&gt;Tags: loss of contact, footing, RCDC, Eccentric Footing Design&lt;/div&gt;
</description></item><item><title>RCDC-Footing</title><link>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing/revision/14</link><pubDate>Fri, 22 Apr 2022 05:59:48 GMT</pubDate><guid isPermaLink="false">6dad98f5-dbc9-4c4d-a9ba-e9da8dc6aa8e:b8d0de3a-5bef-41b5-b7fb-e6dff09549e5</guid><dc:creator>Suvadeep Acharjee</dc:creator><comments>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing#comments</comments><description>Revision 14 posted to RAM | STAAD | ADINA Wiki by Suvadeep Acharjee on 4/22/2022 5:59:48 AM&lt;br /&gt;
&lt;h1&gt;&lt;b&gt;&lt;img alt=" " src="/resized-image/__size/189x60/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1647322192004v2.png" /&gt;&lt;/b&gt;&lt;/h1&gt;
&lt;table style="background-color:#dce5f0;border:0px solid #dce5f0;width:500px;" border="0"&gt;
&lt;tbody&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;span style="font-size:medium;"&gt;&lt;b&gt;Applies To&lt;/b&gt;&lt;/span&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Product(s):&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;STAAD Advanced Concrete Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Version(s):&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Connect Edition&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Environment:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Area:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Concrete Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Subarea:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Footing Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Original Author:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Bentley Technical Support Group&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;/tbody&gt;
&lt;/table&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[While designing for reinforcement requirement]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[Footing Design with tension in Column]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[Eccentric Footing design in RCDC]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[Footing Design with loss of contact condition in RCDC]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[Base pressure calculation in RCDC]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[How the effective self-weight of the footing is calculated?]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;1. How the effective self-weight of the footing is calculated?&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;Effective self-weight of footing is calculated as additional load of footing volume with respect to difference in density of concrete and soil. For more information refer &amp;ldquo;Technical discussion&amp;rdquo; of footing from help Content.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;2. For calculation of two way (punching) shear, footing self-weight is not added to axial load.&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;Concept of Footing punching shear criteria is column punches in the footing. Load from the column punches the column in footing. Self-weight of footing, overburden load do not participate in punching of column as it is a uniformly distributed load, thus it is not considered in design. For more information refer &amp;ldquo;Technical discussion&amp;rdquo; of footing from help Content.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;3. As per design, required reinforcement is 1478/1528 sqmm along L/B direction. Provided reinforcement is T12@175 mm which amounts to 1453 sqmm only for 2.25 m width of footing, whereas the calculation report shows Ast provided as 1583sqmm. Please clarify&lt;/strong&gt;.
&lt;ul&gt;
&lt;li&gt;Width = 2250 mm Ast required = 1478 sqmm Reinforcement provided = T12@175 mm In RCDC the number of bars required are calculated and spacing is calculated. While presenting the spacing rounded to 5 mm. In this example, number of bars as per spacing would be calculated as below &amp;ndash; (2250 / 175 = 12.86 which is 13 spaces). Hence number of bars would be 14. Thus actual Ast-provided would be (14x113.097 = 1584) 1584 sqmm which is more than required.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;4. Please clarify the footing type &amp;ldquo;on raft&amp;rdquo; given in RCDC&lt;/strong&gt;.
&lt;ul&gt;
&lt;li&gt;RCDC designs the isolated footings. The purpose of this options is to maintain the same thickness of first step for all footings if all footing are connected by common raft. This type of footing mostly use in the basement structures. The concept of this type of footing is similar to stepped footing.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;5. How is the volume of trapezoidal footing calculated in RCDC?&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;RCDC calculates the weight of trapezoidal footing as per following formulations, Self-wt. of footing Volume of footing = ((L*B*D) + ((((L*B) + (Lt*Bt))/2)*(D-d))/1000^3 Where, L= Length of footing B= Width of footing D= Depth of footing Lt= Length of footing top Bt= Width of footing top d= depth of sloping area.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;6.&lt;em&gt;In RCDC, the minimum rebar&amp;rsquo;s in Bottom are calculation based on effective Depth of the Foundation (Dff),whereas as per Clause 26.5.2.1 the minimum %Pt&amp;nbsp; is 0.12 of the Gross cross section area. Ast (minimum) as per IS456-200 Clause 26.5.2.1 is 0.12% of the Gross Cross section area.&lt;em&gt;Therefore,&amp;nbsp; for&amp;nbsp; F4 1800 x 1800 x 500 thk. : Ast mini = (0.12/100) x 500 x 1800 = 1080 Sqmm. &lt;em&gt;RCDC Calculations. Area calculation based on Deff. { (0.12/100) x 411 x 1800 = 887.76 Sqmm }. &lt;em&gt;Actually we end up providing less %Pt than required. &amp;lt; 1080 sqmm actual requirement vs 888 sqmm Provided&amp;gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;Please refer below snap extracted from IS 456,&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1598267093444v1.png" /&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Minimum reinforcement is for the total cross section area, thus 0.12% steel is to be provided at top and bottom.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;In your case, top reinforcement is selected and below is the reinforcement given,&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1598267129735v2.png" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;The minimum bottom reinforcement is given as 0.12% and top as 0.06%. Thus In your case, the RCDC will check the total reinforcement to be provided at a given cross section area as 0.12%. here, 0.06% is already provided at top, thus at bottom it will provided as per the 0.12% given by you with deff. Refer below snap of calculation &amp;nbsp;report.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/0410.jpg" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Now, don&amp;rsquo;t select the top reinforcement and maintain the same reinforcement, below is the output&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/3124.jpg" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Reinforcement is provided indirectly as 0.12% with total depth. 0.12 x 500 x 1800/100 = 1080 sqmm.&amp;nbsp; If we take Deff, then 0.141 x 427 x 1800/100 = 1083.72 sqmm. So the final reinforcement required is 1080 sqmm.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Here, the required pt has increased to match with the 0.12% with total D.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;If you want to reduce the Bottom reinforcement, please provide bottom reinforcement as 0.06%&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;br /&gt;&lt;span&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:120px;"&gt;&lt;strong&gt;&lt;em&gt;&amp;nbsp;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;

&lt;div style="font-size: 90%;"&gt;Tags: loss of contact, footing, RCDC, Eccentric Footing Design&lt;/div&gt;
</description></item><item><title>RCDC-Footing</title><link>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing/revision/13</link><pubDate>Mon, 28 Mar 2022 18:00:44 GMT</pubDate><guid isPermaLink="false">6dad98f5-dbc9-4c4d-a9ba-e9da8dc6aa8e:b8d0de3a-5bef-41b5-b7fb-e6dff09549e5</guid><dc:creator>Abhisek M</dc:creator><comments>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing#comments</comments><description>Revision 13 posted to RAM | STAAD | ADINA Wiki by Abhisek M on 3/28/2022 6:00:44 PM&lt;br /&gt;
&lt;h1&gt;&lt;b&gt;&lt;img alt=" " src="/resized-image/__size/189x60/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1647322192004v2.png" /&gt;&lt;/b&gt;&lt;/h1&gt;
&lt;table style="background-color:#dce5f0;border:0px solid #dce5f0;width:500px;" border="0"&gt;
&lt;tbody&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;span style="font-size:medium;"&gt;&lt;b&gt;Applies To&lt;/b&gt;&lt;/span&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Product(s):&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;STAAD Advanced Concrete Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Version(s):&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Connect Edition&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Environment:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Area:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Concrete Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Subarea:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Footing Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Original Author:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Bentley Technical Support Group&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;/tbody&gt;
&lt;/table&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[While designing for reinforcement requirement]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[Footing Design with tension in Column]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[Eccentric Footing design in RCDC]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[Footing Design with loss of contact condition in RCDC]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;[[Base pressure calculation in RCDC]]&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;1. How the effective self-weight of the footing is calculated?&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;Effective self-weight of footing is calculated as additional load of footing volume with respect to difference in density of concrete and soil. For more information refer &amp;ldquo;Technical discussion&amp;rdquo; of footing from help Content.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;2. For calculation of two way (punching) shear, footing self-weight is not added to axial load.&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;Concept of Footing punching shear criteria is column punches in the footing. Load from the column punches the column in footing. Self-weight of footing, overburden load do not participate in punching of column as it is a uniformly distributed load, thus it is not considered in design. For more information refer &amp;ldquo;Technical discussion&amp;rdquo; of footing from help Content.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;3. As per design, required reinforcement is 1478/1528 sqmm along L/B direction. Provided reinforcement is T12@175 mm which amounts to 1453 sqmm only for 2.25 m width of footing, whereas the calculation report shows Ast provided as 1583sqmm. Please clarify&lt;/strong&gt;.
&lt;ul&gt;
&lt;li&gt;Width = 2250 mm Ast required = 1478 sqmm Reinforcement provided = T12@175 mm In RCDC the number of bars required are calculated and spacing is calculated. While presenting the spacing rounded to 5 mm. In this example, number of bars as per spacing would be calculated as below &amp;ndash; (2250 / 175 = 12.86 which is 13 spaces). Hence number of bars would be 14. Thus actual Ast-provided would be (14x113.097 = 1584) 1584 sqmm which is more than required.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;4. Please clarify the footing type &amp;ldquo;on raft&amp;rdquo; given in RCDC&lt;/strong&gt;.
&lt;ul&gt;
&lt;li&gt;RCDC designs the isolated footings. The purpose of this options is to maintain the same thickness of first step for all footings if all footing are connected by common raft. This type of footing mostly use in the basement structures. The concept of this type of footing is similar to stepped footing.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;5. How is the volume of trapezoidal footing calculated in RCDC?&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;RCDC calculates the weight of trapezoidal footing as per following formulations, Self-wt. of footing Volume of footing = ((L*B*D) + ((((L*B) + (Lt*Bt))/2)*(D-d))/1000^3 Where, L= Length of footing B= Width of footing D= Depth of footing Lt= Length of footing top Bt= Width of footing top d= depth of sloping area.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;6.&lt;em&gt;In RCDC, the minimum rebar&amp;rsquo;s in Bottom are calculation based on effective Depth of the Foundation (Dff),whereas as per Clause 26.5.2.1 the minimum %Pt&amp;nbsp; is 0.12 of the Gross cross section area. Ast (minimum) as per IS456-200 Clause 26.5.2.1 is 0.12% of the Gross Cross section area.&lt;em&gt;Therefore,&amp;nbsp; for&amp;nbsp; F4 1800 x 1800 x 500 thk. : Ast mini = (0.12/100) x 500 x 1800 = 1080 Sqmm. &lt;em&gt;RCDC Calculations. Area calculation based on Deff. { (0.12/100) x 411 x 1800 = 887.76 Sqmm }. &lt;em&gt;Actually we end up providing less %Pt than required. &amp;lt; 1080 sqmm actual requirement vs 888 sqmm Provided&amp;gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;Please refer below snap extracted from IS 456,&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1598267093444v1.png" /&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Minimum reinforcement is for the total cross section area, thus 0.12% steel is to be provided at top and bottom.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;In your case, top reinforcement is selected and below is the reinforcement given,&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1598267129735v2.png" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;The minimum bottom reinforcement is given as 0.12% and top as 0.06%. Thus In your case, the RCDC will check the total reinforcement to be provided at a given cross section area as 0.12%. here, 0.06% is already provided at top, thus at bottom it will provided as per the 0.12% given by you with deff. Refer below snap of calculation &amp;nbsp;report.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/0410.jpg" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Now, don&amp;rsquo;t select the top reinforcement and maintain the same reinforcement, below is the output&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/3124.jpg" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Reinforcement is provided indirectly as 0.12% with total depth. 0.12 x 500 x 1800/100 = 1080 sqmm.&amp;nbsp; If we take Deff, then 0.141 x 427 x 1800/100 = 1083.72 sqmm. So the final reinforcement required is 1080 sqmm.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Here, the required pt has increased to match with the 0.12% with total D.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;If you want to reduce the Bottom reinforcement, please provide bottom reinforcement as 0.06%&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;br /&gt;&lt;span&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:120px;"&gt;&lt;strong&gt;&lt;em&gt;&amp;nbsp;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;

&lt;div style="font-size: 90%;"&gt;Tags: loss of contact, footing, RCDC, Eccentric Footing Design&lt;/div&gt;
</description></item><item><title>RCDC-Footing</title><link>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing/revision/12</link><pubDate>Fri, 25 Mar 2022 11:44:17 GMT</pubDate><guid isPermaLink="false">6dad98f5-dbc9-4c4d-a9ba-e9da8dc6aa8e:b8d0de3a-5bef-41b5-b7fb-e6dff09549e5</guid><dc:creator>Abhisek M</dc:creator><comments>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing#comments</comments><description>Revision 12 posted to RAM | STAAD | ADINA Wiki by Abhisek M on 3/25/2022 11:44:17 AM&lt;br /&gt;
&lt;h1&gt;&lt;b&gt;&lt;img alt=" " src="/resized-image/__size/189x60/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1647322192004v2.png" /&gt;&lt;/b&gt;&lt;/h1&gt;
&lt;table style="background-color:#dce5f0;border:0px solid #dce5f0;width:500px;" border="0"&gt;
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&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
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&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;span style="font-size:medium;"&gt;&lt;b&gt;Applies To&lt;/b&gt;&lt;/span&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
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&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
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&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Product(s):&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;STAAD Advanced Concrete Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Version(s):&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Connect Edition&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Environment:&lt;/strong&gt;&lt;/td&gt;
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&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Area:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Concrete Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Subarea:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Footing Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Original Author:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Bentley Technical Support Group&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
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&lt;p style="margin:0in 0in 0pt;"&gt;&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;11. [[While designing for reinforcement requirement]]&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;1. How the effective self-weight of the footing is calculated?&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;Effective self-weight of footing is calculated as additional load of footing volume with respect to difference in density of concrete and soil. For more information refer &amp;ldquo;Technical discussion&amp;rdquo; of footing from help Content.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;2. For calculation of two way (punching) shear, footing self-weight is not added to axial load.&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;Concept of Footing punching shear criteria is column punches in the footing. Load from the column punches the column in footing. Self-weight of footing, overburden load do not participate in punching of column as it is a uniformly distributed load, thus it is not considered in design. For more information refer &amp;ldquo;Technical discussion&amp;rdquo; of footing from help Content.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;3. As per design, required reinforcement is 1478/1528 sqmm along L/B direction. Provided reinforcement is T12@175 mm which amounts to 1453 sqmm only for 2.25 m width of footing, whereas the calculation report shows Ast provided as 1583sqmm. Please clarify&lt;/strong&gt;.
&lt;ul&gt;
&lt;li&gt;Width = 2250 mm Ast required = 1478 sqmm Reinforcement provided = T12@175 mm In RCDC the number of bars required are calculated and spacing is calculated. While presenting the spacing rounded to 5 mm. In this example, number of bars as per spacing would be calculated as below &amp;ndash; (2250 / 175 = 12.86 which is 13 spaces). Hence number of bars would be 14. Thus actual Ast-provided would be (14x113.097 = 1584) 1584 sqmm which is more than required.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;4. Please clarify the footing type &amp;ldquo;on raft&amp;rdquo; given in RCDC&lt;/strong&gt;.
&lt;ul&gt;
&lt;li&gt;RCDC designs the isolated footings. The purpose of this options is to maintain the same thickness of first step for all footings if all footing are connected by common raft. This type of footing mostly use in the basement structures. The concept of this type of footing is similar to stepped footing.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;5. How is the volume of trapezoidal footing calculated in RCDC?&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;RCDC calculates the weight of trapezoidal footing as per following formulations, Self-wt. of footing Volume of footing = ((L*B*D) + ((((L*B) + (Lt*Bt))/2)*(D-d))/1000^3 Where, L= Length of footing B= Width of footing D= Depth of footing Lt= Length of footing top Bt= Width of footing top d= depth of sloping area.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;6.&lt;em&gt;In RCDC, the minimum rebar&amp;rsquo;s in Bottom are calculation based on effective Depth of the Foundation (Dff),whereas as per Clause 26.5.2.1 the minimum %Pt&amp;nbsp; is 0.12 of the Gross cross section area. Ast (minimum) as per IS456-200 Clause 26.5.2.1 is 0.12% of the Gross Cross section area.&lt;em&gt;Therefore,&amp;nbsp; for&amp;nbsp; F4 1800 x 1800 x 500 thk. : Ast mini = (0.12/100) x 500 x 1800 = 1080 Sqmm. &lt;em&gt;RCDC Calculations. Area calculation based on Deff. { (0.12/100) x 411 x 1800 = 887.76 Sqmm }. &lt;em&gt;Actually we end up providing less %Pt than required. &amp;lt; 1080 sqmm actual requirement vs 888 sqmm Provided&amp;gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;Please refer below snap extracted from IS 456,&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1598267093444v1.png" /&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Minimum reinforcement is for the total cross section area, thus 0.12% steel is to be provided at top and bottom.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;In your case, top reinforcement is selected and below is the reinforcement given,&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1598267129735v2.png" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;The minimum bottom reinforcement is given as 0.12% and top as 0.06%. Thus In your case, the RCDC will check the total reinforcement to be provided at a given cross section area as 0.12%. here, 0.06% is already provided at top, thus at bottom it will provided as per the 0.12% given by you with deff. Refer below snap of calculation &amp;nbsp;report.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/0410.jpg" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Now, don&amp;rsquo;t select the top reinforcement and maintain the same reinforcement, below is the output&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/3124.jpg" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Reinforcement is provided indirectly as 0.12% with total depth. 0.12 x 500 x 1800/100 = 1080 sqmm.&amp;nbsp; If we take Deff, then 0.141 x 427 x 1800/100 = 1083.72 sqmm. So the final reinforcement required is 1080 sqmm.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Here, the required pt has increased to match with the 0.12% with total D.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;If you want to reduce the Bottom reinforcement, please provide bottom reinforcement as 0.06%&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:30px;"&gt;&lt;strong&gt;7. &lt;em&gt;Can RCDC design the footings for If there is tension in the column due to lateral loads? &lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;Yes, RCDC can design the footing if column having tensile forces. User can design the footing with or without Loss of Contact options if there is tension in column OR one of the corners in footing is in tension.&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;Without loss of contact, RCDC will try to maintain the +ve pressure at all four corners of footing by increasing the self-weight. It is recommended to consider overburden to reduce the footing size in this case.&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;With loss of contact, RCDC will try to maintain the LOC within permissible limits and it will design the footing.&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;em&gt;It will also design and provide the top reinforcement if required in both the cases.&lt;/em&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;em&gt;&lt;/em&gt;&lt;/p&gt;
&lt;p style="padding-left:30px;"&gt;&lt;strong&gt;8.&lt;/strong&gt;&lt;em&gt;&lt;span&gt;&lt;strong&gt;Can We design Eccentric Footing in RCDC?&lt;/strong&gt; &lt;/span&gt;&lt;/em&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Yes, RCDC can design eccentric footing. Refer below link for more details,&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;Eccentric Footing Design&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;a href="/products/ram-staad/m/structural_analysis_and_design_gallery/274459"&gt;https://communities.bentley.com/products/ram-staad/m/structural_analysis_and_design_gallery/274459&lt;/a&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;/p&gt;
&lt;p style="padding-left:30px;"&gt;&lt;strong&gt;9. &lt;em&gt;What is Loss of contact? How RCDC perform the design of footing if LOC is selected?&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;RCDC allow user to provide permissible limits for the loss of contact. If in any case due to tension in footing or heavy lateral moments, corners of the footings experience the -ve pressure. -ve pressure could be at corner or one of the sides of footing. i.e. two adjacent corners with -ve pressure. Technically, maximum 50% LOC is allowed. Thus, maximum limit in RCDC for LOC is 50%. User can provide the % LOC as per its design requirements. If there is LOC, top reinforcement would be design as per the bending moment at top face of footing due to loss of contact.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;For more details, procedure and validation problems, please refer below link.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;Footing design with LOC&lt;/p&gt;
&lt;p style="padding-left:120px;"&gt;&lt;strong&gt;&lt;em&gt;&lt;a href="/products/ram-staad/m/structural_analysis_and_design_gallery/274312"&gt;https://communities.bentley.com/products/ram-staad/m/structural_analysis_and_design_gallery/274312&lt;/a&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:120px;"&gt;&lt;strong&gt;&lt;em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:30px;"&gt;&lt;strong&gt;&lt;em&gt;10.&lt;em&gt;&lt;span&gt;Can you explain the various options available for pressure calculation in RCDC footing design?&lt;/span&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;RCDC provides following options to calculate base pressure,&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;Average Pressure&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;Maximum Pressure&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;Factored SBC&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;Above options are explained below with example:&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1605350325737v2.png" /&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1605350336098v3.png" /&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1605350348030v4.png" /&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:60px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
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&lt;p style="padding-left:120px;"&gt;&lt;strong&gt;&lt;em&gt;&amp;nbsp;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;

&lt;div style="font-size: 90%;"&gt;Tags: loss of contact, footing, RCDC, Eccentric Footing Design&lt;/div&gt;
</description></item><item><title>RCDC-Footing</title><link>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing/revision/11</link><pubDate>Wed, 16 Mar 2022 04:22:28 GMT</pubDate><guid isPermaLink="false">6dad98f5-dbc9-4c4d-a9ba-e9da8dc6aa8e:b8d0de3a-5bef-41b5-b7fb-e6dff09549e5</guid><dc:creator>Aaradhya Rahate</dc:creator><comments>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing#comments</comments><description>Revision 11 posted to RAM | STAAD | ADINA Wiki by Aaradhya Rahate on 3/16/2022 4:22:28 AM&lt;br /&gt;
&lt;h1&gt;&lt;b&gt;&lt;img alt=" " src="/resized-image/__size/189x60/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1647322192004v2.png" /&gt;&lt;/b&gt;&lt;/h1&gt;
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&lt;td style="text-align:right;"&gt;&lt;span style="font-size:medium;"&gt;&lt;b&gt;Applies To&lt;/b&gt;&lt;/span&gt;&lt;/td&gt;
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&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Product(s):&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;STAAD Advanced Concrete Design&lt;/td&gt;
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&lt;td style="text-align:right;"&gt;&lt;strong&gt;Version(s):&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Connect Edition&lt;/td&gt;
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&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Environment:&lt;/strong&gt;&lt;/td&gt;
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&lt;td style="text-align:right;"&gt;&lt;strong&gt;Area:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Concrete Design&lt;/td&gt;
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&lt;td style="text-align:right;"&gt;&lt;strong&gt;Subarea:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Footing Design&lt;/td&gt;
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&lt;td style="text-align:right;"&gt;&lt;strong&gt;Original Author:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Bentley Technical Support Group&lt;/td&gt;
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&lt;p style="margin:0in 0in 0pt;"&gt;&lt;/p&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;11. [[While designing for reinforcement requirement]]&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;1. How the effective self-weight of the footing is calculated?&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;Effective self-weight of footing is calculated as additional load of footing volume with respect to difference in density of concrete and soil. For more information refer &amp;ldquo;Technical discussion&amp;rdquo; of footing from help Content.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;2. For calculation of two way (punching) shear, footing self-weight is not added to axial load.&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;Concept of Footing punching shear criteria is column punches in the footing. Load from the column punches the column in footing. Self-weight of footing, overburden load do not participate in punching of column as it is a uniformly distributed load, thus it is not considered in design. For more information refer &amp;ldquo;Technical discussion&amp;rdquo; of footing from help Content.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;3. As per design, required reinforcement is 1478/1528 sqmm along L/B direction. Provided reinforcement is T12@175 mm which amounts to 1453 sqmm only for 2.25 m width of footing, whereas the calculation report shows Ast provided as 1583sqmm. Please clarify&lt;/strong&gt;.
&lt;ul&gt;
&lt;li&gt;Width = 2250 mm Ast required = 1478 sqmm Reinforcement provided = T12@175 mm In RCDC the number of bars required are calculated and spacing is calculated. While presenting the spacing rounded to 5 mm. In this example, number of bars as per spacing would be calculated as below &amp;ndash; (2250 / 175 = 12.86 which is 13 spaces). Hence number of bars would be 14. Thus actual Ast-provided would be (14x113.097 = 1584) 1584 sqmm which is more than required.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;4. Please clarify the footing type &amp;ldquo;on raft&amp;rdquo; given in RCDC&lt;/strong&gt;.
&lt;ul&gt;
&lt;li&gt;RCDC designs the isolated footings. The purpose of this options is to maintain the same thickness of first step for all footings if all footing are connected by common raft. This type of footing mostly use in the basement structures. The concept of this type of footing is similar to stepped footing.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;5. How is the volume of trapezoidal footing calculated in RCDC?&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;RCDC calculates the weight of trapezoidal footing as per following formulations, Self-wt. of footing Volume of footing = ((L*B*D) + ((((L*B) + (Lt*Bt))/2)*(D-d))/1000^3 Where, L= Length of footing B= Width of footing D= Depth of footing Lt= Length of footing top Bt= Width of footing top d= depth of sloping area.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;6.&lt;em&gt;In RCDC, the minimum rebar&amp;rsquo;s in Bottom are calculation based on effective Depth of the Foundation (Dff),whereas as per Clause 26.5.2.1 the minimum %Pt&amp;nbsp; is 0.12 of the Gross cross section area. Ast (minimum) as per IS456-200 Clause 26.5.2.1 is 0.12% of the Gross Cross section area.&lt;em&gt;Therefore,&amp;nbsp; for&amp;nbsp; F4 1800 x 1800 x 500 thk. : Ast mini = (0.12/100) x 500 x 1800 = 1080 Sqmm. &lt;em&gt;RCDC Calculations. Area calculation based on Deff. { (0.12/100) x 411 x 1800 = 887.76 Sqmm }. &lt;em&gt;Actually we end up providing less %Pt than required. &amp;lt; 1080 sqmm actual requirement vs 888 sqmm Provided&amp;gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;Please refer below snap extracted from IS 456,&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1598267093444v1.png" /&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Minimum reinforcement is for the total cross section area, thus 0.12% steel is to be provided at top and bottom.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;In your case, top reinforcement is selected and below is the reinforcement given,&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1598267129735v2.png" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;The minimum bottom reinforcement is given as 0.12% and top as 0.06%. Thus In your case, the RCDC will check the total reinforcement to be provided at a given cross section area as 0.12%. here, 0.06% is already provided at top, thus at bottom it will provided as per the 0.12% given by you with deff. Refer below snap of calculation &amp;nbsp;report.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/0410.jpg" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Now, don&amp;rsquo;t select the top reinforcement and maintain the same reinforcement, below is the output&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/3124.jpg" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Reinforcement is provided indirectly as 0.12% with total depth. 0.12 x 500 x 1800/100 = 1080 sqmm.&amp;nbsp; If we take Deff, then 0.141 x 427 x 1800/100 = 1083.72 sqmm. So the final reinforcement required is 1080 sqmm.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Here, the required pt has increased to match with the 0.12% with total D.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;If you want to reduce the Bottom reinforcement, please provide bottom reinforcement as 0.06%&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:30px;"&gt;&lt;strong&gt;7. &lt;em&gt;Can RCDC design the footings for If there is tension in the column due to lateral loads? &lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;Yes, RCDC can design the footing if column having tensile forces. User can design the footing with or without Loss of Contact options if there is tension in column OR one of the corners in footing is in tension.&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;Without loss of contact, RCDC will try to maintain the +ve pressure at all four corners of footing by increasing the self-weight. It is recommended to consider overburden to reduce the footing size in this case.&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;With loss of contact, RCDC will try to maintain the LOC within permissible limits and it will design the footing.&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;em&gt;It will also design and provide the top reinforcement if required in both the cases.&lt;/em&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;em&gt;&lt;/em&gt;&lt;/p&gt;
&lt;p style="padding-left:30px;"&gt;&lt;strong&gt;8.&lt;/strong&gt;&lt;em&gt;&lt;span&gt;&lt;strong&gt;Can We design Eccentric Footing in RCDC?&lt;/strong&gt; &lt;/span&gt;&lt;/em&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Yes, RCDC can design eccentric footing. Refer below link for more details,&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;Eccentric Footing Design&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;a href="/products/ram-staad/m/structural_analysis_and_design_gallery/274459"&gt;https://communities.bentley.com/products/ram-staad/m/structural_analysis_and_design_gallery/274459&lt;/a&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;/p&gt;
&lt;p style="padding-left:30px;"&gt;&lt;strong&gt;9. &lt;em&gt;What is Loss of contact? How RCDC perform the design of footing if LOC is selected?&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;RCDC allow user to provide permissible limits for the loss of contact. If in any case due to tension in footing or heavy lateral moments, corners of the footings experience the -ve pressure. -ve pressure could be at corner or one of the sides of footing. i.e. two adjacent corners with -ve pressure. Technically, maximum 50% LOC is allowed. Thus, maximum limit in RCDC for LOC is 50%. User can provide the % LOC as per its design requirements. If there is LOC, top reinforcement would be design as per the bending moment at top face of footing due to loss of contact.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;For more details, procedure and validation problems, please refer below link.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;Footing design with LOC&lt;/p&gt;
&lt;p style="padding-left:120px;"&gt;&lt;strong&gt;&lt;em&gt;&lt;a href="/products/ram-staad/m/structural_analysis_and_design_gallery/274312"&gt;https://communities.bentley.com/products/ram-staad/m/structural_analysis_and_design_gallery/274312&lt;/a&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:120px;"&gt;&lt;strong&gt;&lt;em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:30px;"&gt;&lt;strong&gt;&lt;em&gt;10.&lt;em&gt;&lt;span&gt;Can you explain the various options available for pressure calculation in RCDC footing design?&lt;/span&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;RCDC provides following options to calculate base pressure,&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;Average Pressure&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;Maximum Pressure&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;Factored SBC&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;Above options are explained below with example:&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1605350325737v2.png" /&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1605350336098v3.png" /&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1605350348030v4.png" /&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:60px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;11.&amp;nbsp;&amp;nbsp;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;em&gt;&lt;strong&gt;While designing for reinforcement requirement, it was observed that RCDC considers only super-structure support reaction. Ideally the effective extra weight of foundation replacing the existing soil should also be considered for the vertical load. So the additional loading from volume of the RCC potion under the ground level with an effective density [concrete density (25 kN/***) &amp;ndash; soil density (18 kN/***)] should be added up with super-structure reaction.&lt;/strong&gt;&lt;/em&gt;&lt;/p&gt;
&lt;p style="padding-left:60px;"&gt;&lt;em&gt;&lt;/em&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;For sizing check of footings where maximum and minimum soil pressure (or loss of contact) is checked (and also other checks), we add the weight of footing and weight of soil. Following are possible cases &amp;ndash;&lt;/p&gt;
&lt;p style="padding-left:120px;"&gt;1. User chooses &amp;lsquo;Yes&amp;rsquo; to option &amp;ndash; Consider Overburden &amp;ndash; In this option we add load of soil and self-weight of footing&lt;/p&gt;
&lt;p style="padding-left:120px;"&gt;2. User chooses &amp;lsquo;No&amp;rsquo; to option &amp;ndash; Consider Overburden &amp;ndash; In this option we add self-weight of footing&lt;/p&gt;
&lt;p&gt;&amp;nbsp;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;When it comes to design of cross-section, the BM and shear is calculated using the pressure from bottom. In this case, the vertical load due to self-weight of footing and soil is uniformly distributed and it gets off-set by equivalent pressure from below. So net pressure causing the bending from bottom is the pressure due to reactions from super-structure load. In other words, if one considers pressure from bottom (including soil and self-weight) for calculation of BM and shear then, one will have to deduct the load from top (due to self-weight and soil) as it would oppose it. Hence in the design of cross-section, the weight of footing and soil have no impact.&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p style="padding-left:30px;"&gt;&lt;/p&gt;
&lt;p style="padding-left:120px;"&gt;&lt;strong&gt;&lt;em&gt;&amp;nbsp;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;

&lt;div style="font-size: 90%;"&gt;Tags: loss of contact, footing, RCDC, Eccentric Footing Design&lt;/div&gt;
</description></item><item><title>RCDC-Footing</title><link>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing/revision/10</link><pubDate>Tue, 15 Mar 2022 05:33:35 GMT</pubDate><guid isPermaLink="false">6dad98f5-dbc9-4c4d-a9ba-e9da8dc6aa8e:b8d0de3a-5bef-41b5-b7fb-e6dff09549e5</guid><dc:creator>Abhisek M</dc:creator><comments>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing#comments</comments><description>Revision 10 posted to RAM | STAAD | ADINA Wiki by Abhisek M on 3/15/2022 5:33:35 AM&lt;br /&gt;
&lt;h1&gt;&lt;b&gt;&lt;img alt=" " src="/resized-image/__size/189x60/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1647322192004v2.png" /&gt;&lt;/b&gt;&lt;/h1&gt;
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&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;span style="font-size:medium;"&gt;&lt;b&gt;Applies To&lt;/b&gt;&lt;/span&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Product(s):&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;STAAD Advanced Concrete Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Version(s):&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Connect Edition&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Environment:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Area:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Concrete Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Subarea:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Footing Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Original Author:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Bentley Technical Support Group&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
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&lt;/tr&gt;
&lt;/tbody&gt;
&lt;/table&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;1. How the effective self-weight of the footing is calculated?&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;Effective self-weight of footing is calculated as additional load of footing volume with respect to difference in density of concrete and soil. For more information refer &amp;ldquo;Technical discussion&amp;rdquo; of footing from help Content.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;2. For calculation of two way (punching) shear, footing self-weight is not added to axial load.&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;Concept of Footing punching shear criteria is column punches in the footing. Load from the column punches the column in footing. Self-weight of footing, overburden load do not participate in punching of column as it is a uniformly distributed load, thus it is not considered in design. For more information refer &amp;ldquo;Technical discussion&amp;rdquo; of footing from help Content.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;3. As per design, required reinforcement is 1478/1528 sqmm along L/B direction. Provided reinforcement is T12@175 mm which amounts to 1453 sqmm only for 2.25 m width of footing, whereas the calculation report shows Ast provided as 1583sqmm. Please clarify&lt;/strong&gt;.
&lt;ul&gt;
&lt;li&gt;Width = 2250 mm Ast required = 1478 sqmm Reinforcement provided = T12@175 mm In RCDC the number of bars required are calculated and spacing is calculated. While presenting the spacing rounded to 5 mm. In this example, number of bars as per spacing would be calculated as below &amp;ndash; (2250 / 175 = 12.86 which is 13 spaces). Hence number of bars would be 14. Thus actual Ast-provided would be (14x113.097 = 1584) 1584 sqmm which is more than required.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;4. Please clarify the footing type &amp;ldquo;on raft&amp;rdquo; given in RCDC&lt;/strong&gt;.
&lt;ul&gt;
&lt;li&gt;RCDC designs the isolated footings. The purpose of this options is to maintain the same thickness of first step for all footings if all footing are connected by common raft. This type of footing mostly use in the basement structures. The concept of this type of footing is similar to stepped footing.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;5. How is the volume of trapezoidal footing calculated in RCDC?&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;RCDC calculates the weight of trapezoidal footing as per following formulations, Self-wt. of footing Volume of footing = ((L*B*D) + ((((L*B) + (Lt*Bt))/2)*(D-d))/1000^3 Where, L= Length of footing B= Width of footing D= Depth of footing Lt= Length of footing top Bt= Width of footing top d= depth of sloping area.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;6.&lt;em&gt;In RCDC, the minimum rebar&amp;rsquo;s in Bottom are calculation based on effective Depth of the Foundation (Dff),whereas as per Clause 26.5.2.1 the minimum %Pt&amp;nbsp; is 0.12 of the Gross cross section area. Ast (minimum) as per IS456-200 Clause 26.5.2.1 is 0.12% of the Gross Cross section area.&lt;em&gt;Therefore,&amp;nbsp; for&amp;nbsp; F4 1800 x 1800 x 500 thk. : Ast mini = (0.12/100) x 500 x 1800 = 1080 Sqmm. &lt;em&gt;RCDC Calculations. Area calculation based on Deff. { (0.12/100) x 411 x 1800 = 887.76 Sqmm }. &lt;em&gt;Actually we end up providing less %Pt than required. &amp;lt; 1080 sqmm actual requirement vs 888 sqmm Provided&amp;gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;Please refer below snap extracted from IS 456,&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1598267093444v1.png" /&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Minimum reinforcement is for the total cross section area, thus 0.12% steel is to be provided at top and bottom.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;In your case, top reinforcement is selected and below is the reinforcement given,&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1598267129735v2.png" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;The minimum bottom reinforcement is given as 0.12% and top as 0.06%. Thus In your case, the RCDC will check the total reinforcement to be provided at a given cross section area as 0.12%. here, 0.06% is already provided at top, thus at bottom it will provided as per the 0.12% given by you with deff. Refer below snap of calculation &amp;nbsp;report.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/0410.jpg" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Now, don&amp;rsquo;t select the top reinforcement and maintain the same reinforcement, below is the output&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/3124.jpg" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Reinforcement is provided indirectly as 0.12% with total depth. 0.12 x 500 x 1800/100 = 1080 sqmm.&amp;nbsp; If we take Deff, then 0.141 x 427 x 1800/100 = 1083.72 sqmm. So the final reinforcement required is 1080 sqmm.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Here, the required pt has increased to match with the 0.12% with total D.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;If you want to reduce the Bottom reinforcement, please provide bottom reinforcement as 0.06%&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:30px;"&gt;&lt;strong&gt;7. &lt;em&gt;Can RCDC design the footings for If there is tension in the column due to lateral loads? &lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;Yes, RCDC can design the footing if column having tensile forces. User can design the footing with or without Loss of Contact options if there is tension in column OR one of the corners in footing is in tension.&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;Without loss of contact, RCDC will try to maintain the +ve pressure at all four corners of footing by increasing the self-weight. It is recommended to consider overburden to reduce the footing size in this case.&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;With loss of contact, RCDC will try to maintain the LOC within permissible limits and it will design the footing.&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;em&gt;It will also design and provide the top reinforcement if required in both the cases.&lt;/em&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;em&gt;&lt;/em&gt;&lt;/p&gt;
&lt;p style="padding-left:30px;"&gt;&lt;strong&gt;8.&lt;/strong&gt;&lt;em&gt;&lt;span&gt;&lt;strong&gt;Can We design Eccentric Footing in RCDC?&lt;/strong&gt; &lt;/span&gt;&lt;/em&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Yes, RCDC can design eccentric footing. Refer below link for more details,&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;Eccentric Footing Design&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;a href="/products/ram-staad/m/structural_analysis_and_design_gallery/274459"&gt;https://communities.bentley.com/products/ram-staad/m/structural_analysis_and_design_gallery/274459&lt;/a&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;/p&gt;
&lt;p style="padding-left:30px;"&gt;&lt;strong&gt;9. &lt;em&gt;What is Loss of contact? How RCDC perform the design of footing if LOC is selected?&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;RCDC allow user to provide permissible limits for the loss of contact. If in any case due to tension in footing or heavy lateral moments, corners of the footings experience the -ve pressure. -ve pressure could be at corner or one of the sides of footing. i.e. two adjacent corners with -ve pressure. Technically, maximum 50% LOC is allowed. Thus, maximum limit in RCDC for LOC is 50%. User can provide the % LOC as per its design requirements. If there is LOC, top reinforcement would be design as per the bending moment at top face of footing due to loss of contact.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;For more details, procedure and validation problems, please refer below link.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;Footing design with LOC&lt;/p&gt;
&lt;p style="padding-left:120px;"&gt;&lt;strong&gt;&lt;em&gt;&lt;a href="/products/ram-staad/m/structural_analysis_and_design_gallery/274312"&gt;https://communities.bentley.com/products/ram-staad/m/structural_analysis_and_design_gallery/274312&lt;/a&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:120px;"&gt;&lt;strong&gt;&lt;em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:30px;"&gt;&lt;strong&gt;&lt;em&gt;10.&lt;em&gt;&lt;span&gt;Can you explain the various options available for pressure calculation in RCDC footing design?&lt;/span&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;RCDC provides following options to calculate base pressure,&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;Average Pressure&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;Maximum Pressure&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;Factored SBC&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;Above options are explained below with example:&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1605350325737v2.png" /&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1605350336098v3.png" /&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1605350348030v4.png" /&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:60px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;11.&amp;nbsp;&amp;nbsp;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;em&gt;&lt;strong&gt;While designing for reinforcement requirement, it was observed that RCDC considers only super-structure support reaction. Ideally the effective extra weight of foundation replacing the existing soil should also be considered for the vertical load. So the additional loading from volume of the RCC potion under the ground level with an effective density [concrete density (25 kN/***) &amp;ndash; soil density (18 kN/***)] should be added up with super-structure reaction.&lt;/strong&gt;&lt;/em&gt;&lt;/p&gt;
&lt;p style="padding-left:60px;"&gt;&lt;em&gt;&lt;/em&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;For sizing check of footings where maximum and minimum soil pressure (or loss of contact) is checked (and also other checks), we add the weight of footing and weight of soil. Following are possible cases &amp;ndash;&lt;/p&gt;
&lt;p style="padding-left:120px;"&gt;1. User chooses &amp;lsquo;Yes&amp;rsquo; to option &amp;ndash; Consider Overburden &amp;ndash; In this option we add load of soil and self-weight of footing&lt;/p&gt;
&lt;p style="padding-left:120px;"&gt;2. User chooses &amp;lsquo;No&amp;rsquo; to option &amp;ndash; Consider Overburden &amp;ndash; In this option we add self-weight of footing&lt;/p&gt;
&lt;p&gt;&amp;nbsp;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;When it comes to design of cross-section, the BM and shear is calculated using the pressure from bottom. In this case, the vertical load due to self-weight of footing and soil is uniformly distributed and it gets off-set by equivalent pressure from below. So net pressure causing the bending from bottom is the pressure due to reactions from super-structure load. In other words, if one considers pressure from bottom (including soil and self-weight) for calculation of BM and shear then, one will have to deduct the load from top (due to self-weight and soil) as it would oppose it. Hence in the design of cross-section, the weight of footing and soil have no impact.&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p style="padding-left:30px;"&gt;&lt;/p&gt;
&lt;p style="padding-left:120px;"&gt;&lt;strong&gt;&lt;em&gt;&amp;nbsp;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;

&lt;div style="font-size: 90%;"&gt;Tags: loss of contact, footing, RCDC, Eccentric Footing Design&lt;/div&gt;
</description></item><item><title>RCDC-Footing</title><link>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing/revision/9</link><pubDate>Tue, 15 Mar 2022 05:29:01 GMT</pubDate><guid isPermaLink="false">6dad98f5-dbc9-4c4d-a9ba-e9da8dc6aa8e:b8d0de3a-5bef-41b5-b7fb-e6dff09549e5</guid><dc:creator>Abhisek M</dc:creator><comments>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing#comments</comments><description>Revision 9 posted to RAM | STAAD | ADINA Wiki by Abhisek M on 3/15/2022 5:29:01 AM&lt;br /&gt;
&lt;h1&gt;&lt;b&gt;&lt;img src="/resized-image/__size/189x60/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1647322192004v2.png" alt=" " /&gt;&lt;/b&gt;&lt;/h1&gt;
&lt;table style="background-color:#dce5f0;border:0px solid #dce5f0;width:500px;" border="0"&gt;
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&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
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&lt;td style="text-align:right;"&gt;&lt;b&gt;&lt;/b&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;span style="font-size:medium;"&gt;&lt;b&gt;Applies To&lt;/b&gt;&lt;/span&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
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&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Product(s):&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;STAAD Advanced Concrete Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Version(s):&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Connect Edition&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Environment:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Area:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Concrete Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Subarea:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Footing Design&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;Original Author:&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;Abhisek Mandal, Bentley Technical Support Group&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td style="text-align:right;"&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;td&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;/tbody&gt;
&lt;/table&gt;
&lt;p style="margin:0in 0in 0pt;"&gt;&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;1. How the effective self-weight of the footing is calculated?&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;Effective self-weight of footing is calculated as additional load of footing volume with respect to difference in density of concrete and soil. For more information refer &amp;ldquo;Technical discussion&amp;rdquo; of footing from help Content.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;2. For calculation of two way (punching) shear, footing self-weight is not added to axial load.&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;Concept of Footing punching shear criteria is column punches in the footing. Load from the column punches the column in footing. Self-weight of footing, overburden load do not participate in punching of column as it is a uniformly distributed load, thus it is not considered in design. For more information refer &amp;ldquo;Technical discussion&amp;rdquo; of footing from help Content.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;3. As per design, required reinforcement is 1478/1528 sqmm along L/B direction. Provided reinforcement is T12@175 mm which amounts to 1453 sqmm only for 2.25 m width of footing, whereas the calculation report shows Ast provided as 1583sqmm. Please clarify&lt;/strong&gt;.
&lt;ul&gt;
&lt;li&gt;Width = 2250 mm Ast required = 1478 sqmm Reinforcement provided = T12@175 mm In RCDC the number of bars required are calculated and spacing is calculated. While presenting the spacing rounded to 5 mm. In this example, number of bars as per spacing would be calculated as below &amp;ndash; (2250 / 175 = 12.86 which is 13 spaces). Hence number of bars would be 14. Thus actual Ast-provided would be (14x113.097 = 1584) 1584 sqmm which is more than required.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;4. Please clarify the footing type &amp;ldquo;on raft&amp;rdquo; given in RCDC&lt;/strong&gt;.
&lt;ul&gt;
&lt;li&gt;RCDC designs the isolated footings. The purpose of this options is to maintain the same thickness of first step for all footings if all footing are connected by common raft. This type of footing mostly use in the basement structures. The concept of this type of footing is similar to stepped footing.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;5. How is the volume of trapezoidal footing calculated in RCDC?&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;RCDC calculates the weight of trapezoidal footing as per following formulations, Self-wt. of footing Volume of footing = ((L*B*D) + ((((L*B) + (Lt*Bt))/2)*(D-d))/1000^3 Where, L= Length of footing B= Width of footing D= Depth of footing Lt= Length of footing top Bt= Width of footing top d= depth of sloping area.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;6.&lt;em&gt;In RCDC, the minimum rebar&amp;rsquo;s in Bottom are calculation based on effective Depth of the Foundation (Dff),whereas as per Clause 26.5.2.1 the minimum %Pt&amp;nbsp; is 0.12 of the Gross cross section area. Ast (minimum) as per IS456-200 Clause 26.5.2.1 is 0.12% of the Gross Cross section area.&lt;em&gt;Therefore,&amp;nbsp; for&amp;nbsp; F4 1800 x 1800 x 500 thk. : Ast mini = (0.12/100) x 500 x 1800 = 1080 Sqmm. &lt;em&gt;RCDC Calculations. Area calculation based on Deff. { (0.12/100) x 411 x 1800 = 887.76 Sqmm }. &lt;em&gt;Actually we end up providing less %Pt than required. &amp;lt; 1080 sqmm actual requirement vs 888 sqmm Provided&amp;gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;Please refer below snap extracted from IS 456,&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1598267093444v1.png" /&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Minimum reinforcement is for the total cross section area, thus 0.12% steel is to be provided at top and bottom.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;In your case, top reinforcement is selected and below is the reinforcement given,&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1598267129735v2.png" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;The minimum bottom reinforcement is given as 0.12% and top as 0.06%. Thus In your case, the RCDC will check the total reinforcement to be provided at a given cross section area as 0.12%. here, 0.06% is already provided at top, thus at bottom it will provided as per the 0.12% given by you with deff. Refer below snap of calculation &amp;nbsp;report.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/0410.jpg" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Now, don&amp;rsquo;t select the top reinforcement and maintain the same reinforcement, below is the output&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/3124.jpg" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Reinforcement is provided indirectly as 0.12% with total depth. 0.12 x 500 x 1800/100 = 1080 sqmm.&amp;nbsp; If we take Deff, then 0.141 x 427 x 1800/100 = 1083.72 sqmm. So the final reinforcement required is 1080 sqmm.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Here, the required pt has increased to match with the 0.12% with total D.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;If you want to reduce the Bottom reinforcement, please provide bottom reinforcement as 0.06%&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:30px;"&gt;&lt;strong&gt;7. &lt;em&gt;Can RCDC design the footings for If there is tension in the column due to lateral loads? &lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;Yes, RCDC can design the footing if column having tensile forces. User can design the footing with or without Loss of Contact options if there is tension in column OR one of the corners in footing is in tension.&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;Without loss of contact, RCDC will try to maintain the +ve pressure at all four corners of footing by increasing the self-weight. It is recommended to consider overburden to reduce the footing size in this case.&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;With loss of contact, RCDC will try to maintain the LOC within permissible limits and it will design the footing.&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;em&gt;It will also design and provide the top reinforcement if required in both the cases.&lt;/em&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;em&gt;&lt;/em&gt;&lt;/p&gt;
&lt;p style="padding-left:30px;"&gt;&lt;strong&gt;8.&lt;/strong&gt;&lt;em&gt;&lt;span&gt;&lt;strong&gt;Can We design Eccentric Footing in RCDC?&lt;/strong&gt; &lt;/span&gt;&lt;/em&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Yes, RCDC can design eccentric footing. Refer below link for more details,&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;Eccentric Footing Design&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;a href="/products/ram-staad/m/structural_analysis_and_design_gallery/274459"&gt;https://communities.bentley.com/products/ram-staad/m/structural_analysis_and_design_gallery/274459&lt;/a&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;/p&gt;
&lt;p style="padding-left:30px;"&gt;&lt;strong&gt;9. &lt;em&gt;What is Loss of contact? How RCDC perform the design of footing if LOC is selected?&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;RCDC allow user to provide permissible limits for the loss of contact. If in any case due to tension in footing or heavy lateral moments, corners of the footings experience the -ve pressure. -ve pressure could be at corner or one of the sides of footing. i.e. two adjacent corners with -ve pressure. Technically, maximum 50% LOC is allowed. Thus, maximum limit in RCDC for LOC is 50%. User can provide the % LOC as per its design requirements. If there is LOC, top reinforcement would be design as per the bending moment at top face of footing due to loss of contact.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;For more details, procedure and validation problems, please refer below link.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;Footing design with LOC&lt;/p&gt;
&lt;p style="padding-left:120px;"&gt;&lt;strong&gt;&lt;em&gt;&lt;a href="/products/ram-staad/m/structural_analysis_and_design_gallery/274312"&gt;https://communities.bentley.com/products/ram-staad/m/structural_analysis_and_design_gallery/274312&lt;/a&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:120px;"&gt;&lt;strong&gt;&lt;em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:30px;"&gt;&lt;strong&gt;&lt;em&gt;10.&lt;em&gt;&lt;span&gt;Can you explain the various options available for pressure calculation in RCDC footing design?&lt;/span&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;RCDC provides following options to calculate base pressure,&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;Average Pressure&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;Maximum Pressure&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;Factored SBC&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;Above options are explained below with example:&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1605350325737v2.png" /&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1605350336098v3.png" /&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1605350348030v4.png" /&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:60px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;11.&amp;nbsp;&amp;nbsp;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;em&gt;&lt;strong&gt;While designing for reinforcement requirement, it was observed that RCDC considers only super-structure support reaction. Ideally the effective extra weight of foundation replacing the existing soil should also be considered for the vertical load. So the additional loading from volume of the RCC potion under the ground level with an effective density [concrete density (25 kN/***) &amp;ndash; soil density (18 kN/***)] should be added up with super-structure reaction.&lt;/strong&gt;&lt;/em&gt;&lt;/p&gt;
&lt;p style="padding-left:60px;"&gt;&lt;em&gt;&lt;/em&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;For sizing check of footings where maximum and minimum soil pressure (or loss of contact) is checked (and also other checks), we add the weight of footing and weight of soil. Following are possible cases &amp;ndash;&lt;/p&gt;
&lt;p style="padding-left:120px;"&gt;1. User chooses &amp;lsquo;Yes&amp;rsquo; to option &amp;ndash; Consider Overburden &amp;ndash; In this option we add load of soil and self-weight of footing&lt;/p&gt;
&lt;p style="padding-left:120px;"&gt;2. User chooses &amp;lsquo;No&amp;rsquo; to option &amp;ndash; Consider Overburden &amp;ndash; In this option we add self-weight of footing&lt;/p&gt;
&lt;p&gt;&amp;nbsp;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;When it comes to design of cross-section, the BM and shear is calculated using the pressure from bottom. In this case, the vertical load due to self-weight of footing and soil is uniformly distributed and it gets off-set by equivalent pressure from below. So net pressure causing the bending from bottom is the pressure due to reactions from super-structure load. In other words, if one considers pressure from bottom (including soil and self-weight) for calculation of BM and shear then, one will have to deduct the load from top (due to self-weight and soil) as it would oppose it. Hence in the design of cross-section, the weight of footing and soil have no impact.&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p style="padding-left:30px;"&gt;&lt;/p&gt;
&lt;p style="padding-left:120px;"&gt;&lt;strong&gt;&lt;em&gt;&amp;nbsp;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;

&lt;div style="font-size: 90%;"&gt;Tags: loss of contact, footing, RCDC, Eccentric Footing Design&lt;/div&gt;
</description></item><item><title>RCDC-Footing</title><link>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing/revision/8</link><pubDate>Wed, 22 Dec 2021 08:16:36 GMT</pubDate><guid isPermaLink="false">6dad98f5-dbc9-4c4d-a9ba-e9da8dc6aa8e:b8d0de3a-5bef-41b5-b7fb-e6dff09549e5</guid><dc:creator>Nidhi Valia</dc:creator><comments>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing#comments</comments><description>Revision 8 posted to RAM | STAAD | ADINA Wiki by Nidhi Valia on 12/22/2021 8:16:36 AM&lt;br /&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;1. How the effective self-weight of the footing is calculated?&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;Effective self-weight of footing is calculated as additional load of footing volume with respect to difference in density of concrete and soil. For more information refer &amp;ldquo;Technical discussion&amp;rdquo; of footing from help Content.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;2. For calculation of two way (punching) shear, footing self-weight is not added to axial load.&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;Concept of Footing punching shear criteria is column punches in the footing. Load from the column punches the column in footing. Self-weight of footing, overburden load do not participate in punching of column as it is a uniformly distributed load, thus it is not considered in design. For more information refer &amp;ldquo;Technical discussion&amp;rdquo; of footing from help Content.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;3. As per design, required reinforcement is 1478/1528 sqmm along L/B direction. Provided reinforcement is T12@175 mm which amounts to 1453 sqmm only for 2.25 m width of footing, whereas the calculation report shows Ast provided as 1583sqmm. Please clarify&lt;/strong&gt;.
&lt;ul&gt;
&lt;li&gt;Width = 2250 mm Ast required = 1478 sqmm Reinforcement provided = T12@175 mm In RCDC the number of bars required are calculated and spacing is calculated. While presenting the spacing rounded to 5 mm. In this example, number of bars as per spacing would be calculated as below &amp;ndash; (2250 / 175 = 12.86 which is 13 spaces). Hence number of bars would be 14. Thus actual Ast-provided would be (14x113.097 = 1584) 1584 sqmm which is more than required.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;4. Please clarify the footing type &amp;ldquo;on raft&amp;rdquo; given in RCDC&lt;/strong&gt;.
&lt;ul&gt;
&lt;li&gt;RCDC designs the isolated footings. The purpose of this options is to maintain the same thickness of first step for all footings if all footing are connected by common raft. This type of footing mostly use in the basement structures. The concept of this type of footing is similar to stepped footing.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;5. How is the volume of trapezoidal footing calculated in RCDC?&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;RCDC calculates the weight of trapezoidal footing as per following formulations, Self-wt. of footing Volume of footing = ((L*B*D) + ((((L*B) + (Lt*Bt))/2)*(D-d))/1000^3 Where, L= Length of footing B= Width of footing D= Depth of footing Lt= Length of footing top Bt= Width of footing top d= depth of sloping area.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;6.&lt;em&gt;In RCDC, the minimum rebar&amp;rsquo;s in Bottom are calculation based on effective Depth of the Foundation (Dff),whereas as per Clause 26.5.2.1 the minimum %Pt&amp;nbsp; is 0.12 of the Gross cross section area. Ast (minimum) as per IS456-200 Clause 26.5.2.1 is 0.12% of the Gross Cross section area.&lt;em&gt;Therefore,&amp;nbsp; for&amp;nbsp; F4 1800 x 1800 x 500 thk. : Ast mini = (0.12/100) x 500 x 1800 = 1080 Sqmm. &lt;em&gt;RCDC Calculations. Area calculation based on Deff. { (0.12/100) x 411 x 1800 = 887.76 Sqmm }. &lt;em&gt;Actually we end up providing less %Pt than required. &amp;lt; 1080 sqmm actual requirement vs 888 sqmm Provided&amp;gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;Please refer below snap extracted from IS 456,&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1598267093444v1.png" /&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Minimum reinforcement is for the total cross section area, thus 0.12% steel is to be provided at top and bottom.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;In your case, top reinforcement is selected and below is the reinforcement given,&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1598267129735v2.png" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;The minimum bottom reinforcement is given as 0.12% and top as 0.06%. Thus In your case, the RCDC will check the total reinforcement to be provided at a given cross section area as 0.12%. here, 0.06% is already provided at top, thus at bottom it will provided as per the 0.12% given by you with deff. Refer below snap of calculation &amp;nbsp;report.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/0410.jpg" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Now, don&amp;rsquo;t select the top reinforcement and maintain the same reinforcement, below is the output&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/3124.jpg" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Reinforcement is provided indirectly as 0.12% with total depth. 0.12 x 500 x 1800/100 = 1080 sqmm.&amp;nbsp; If we take Deff, then 0.141 x 427 x 1800/100 = 1083.72 sqmm. So the final reinforcement required is 1080 sqmm.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Here, the required pt has increased to match with the 0.12% with total D.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;If you want to reduce the Bottom reinforcement, please provide bottom reinforcement as 0.06%&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:30px;"&gt;&lt;strong&gt;7. &lt;em&gt;Can RCDC design the footings for If there is tension in the column due to lateral loads? &lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;Yes, RCDC can design the footing if column having tensile forces. User can design the footing with or without Loss of Contact options if there is tension in column OR one of the corners in footing is in tension.&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;Without loss of contact, RCDC will try to maintain the +ve pressure at all four corners of footing by increasing the self-weight. It is recommended to consider overburden to reduce the footing size in this case.&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;With loss of contact, RCDC will try to maintain the LOC within permissible limits and it will design the footing.&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;em&gt;It will also design and provide the top reinforcement if required in both the cases.&lt;/em&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;em&gt;&lt;/em&gt;&lt;/p&gt;
&lt;p style="padding-left:30px;"&gt;&lt;strong&gt;8.&lt;/strong&gt;&lt;em&gt;&lt;span&gt;&lt;strong&gt;Can We design Eccentric Footing in RCDC?&lt;/strong&gt; &lt;/span&gt;&lt;/em&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Yes, RCDC can design eccentric footing. Refer below link for more details,&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;Eccentric Footing Design&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;a href="/products/ram-staad/m/structural_analysis_and_design_gallery/274459"&gt;https://communities.bentley.com/products/ram-staad/m/structural_analysis_and_design_gallery/274459&lt;/a&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;/p&gt;
&lt;p style="padding-left:30px;"&gt;&lt;strong&gt;9. &lt;em&gt;What is Loss of contact? How RCDC perform the design of footing if LOC is selected?&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;RCDC allow user to provide permissible limits for the loss of contact. If in any case due to tension in footing or heavy lateral moments, corners of the footings experience the -ve pressure. -ve pressure could be at corner or one of the sides of footing. i.e. two adjacent corners with -ve pressure. Technically, maximum 50% LOC is allowed. Thus, maximum limit in RCDC for LOC is 50%. User can provide the % LOC as per its design requirements. If there is LOC, top reinforcement would be design as per the bending moment at top face of footing due to loss of contact.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;For more details, procedure and validation problems, please refer below link.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;Footing design with LOC&lt;/p&gt;
&lt;p style="padding-left:120px;"&gt;&lt;strong&gt;&lt;em&gt;&lt;a href="/products/ram-staad/m/structural_analysis_and_design_gallery/274312"&gt;https://communities.bentley.com/products/ram-staad/m/structural_analysis_and_design_gallery/274312&lt;/a&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:120px;"&gt;&lt;strong&gt;&lt;em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:30px;"&gt;&lt;strong&gt;&lt;em&gt;10.&lt;em&gt;&lt;span&gt;Can you explain the various options available for pressure calculation in RCDC footing design?&lt;/span&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;RCDC provides following options to calculate base pressure,&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;Average Pressure&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;Maximum Pressure&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;Factored SBC&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;Above options are explained below with example:&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1605350325737v2.png" /&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1605350336098v3.png" /&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1605350348030v4.png" /&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:60px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;11.&amp;nbsp;&amp;nbsp;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;em&gt;&lt;strong&gt;While designing for reinforcement requirement, it was observed that RCDC considers only super-structure support reaction. Ideally the effective extra weight of foundation replacing the existing soil should also be considered for the vertical load. So the additional loading from volume of the RCC potion under the ground level with an effective density [concrete density (25 kN/***) &amp;ndash; soil density (18 kN/***)] should be added up with super-structure reaction.&lt;/strong&gt;&lt;/em&gt;&lt;/p&gt;
&lt;p style="padding-left:60px;"&gt;&lt;em&gt;&lt;/em&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;For sizing check of footings where maximum and minimum soil pressure (or loss of contact) is checked (and also other checks), we add the weight of footing and weight of soil. Following are possible cases &amp;ndash;&lt;/p&gt;
&lt;p style="padding-left:120px;"&gt;1. User chooses &amp;lsquo;Yes&amp;rsquo; to option &amp;ndash; Consider Overburden &amp;ndash; In this option we add load of soil and self-weight of footing&lt;/p&gt;
&lt;p style="padding-left:120px;"&gt;2. User chooses &amp;lsquo;No&amp;rsquo; to option &amp;ndash; Consider Overburden &amp;ndash; In this option we add self-weight of footing&lt;/p&gt;
&lt;p&gt;&amp;nbsp;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;When it comes to design of cross-section, the BM and shear is calculated using the pressure from bottom. In this case, the vertical load due to self-weight of footing and soil is uniformly distributed and it gets off-set by equivalent pressure from below. So net pressure causing the bending from bottom is the pressure due to reactions from super-structure load. In other words, if one considers pressure from bottom (including soil and self-weight) for calculation of BM and shear then, one will have to deduct the load from top (due to self-weight and soil) as it would oppose it. Hence in the design of cross-section, the weight of footing and soil have no impact.&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p style="padding-left:30px;"&gt;&lt;/p&gt;
&lt;p style="padding-left:120px;"&gt;&lt;strong&gt;&lt;em&gt;&amp;nbsp;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;

&lt;div style="font-size: 90%;"&gt;Tags: loss of contact, footing, RCDC, Eccentric Footing Design&lt;/div&gt;
</description></item><item><title>RCDC-Footing</title><link>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing/revision/7</link><pubDate>Sat, 14 Nov 2020 10:39:40 GMT</pubDate><guid isPermaLink="false">6dad98f5-dbc9-4c4d-a9ba-e9da8dc6aa8e:b8d0de3a-5bef-41b5-b7fb-e6dff09549e5</guid><dc:creator>Abhijeet Gundaye</dc:creator><comments>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing#comments</comments><description>Revision 7 posted to RAM | STAAD | ADINA Wiki by Abhijeet Gundaye on 11/14/2020 10:39:40 AM&lt;br /&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;1. How the effective self-weight of the footing is calculated?&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;Effective self-weight of footing is calculated as additional load of footing volume with respect to difference in density of concrete and soil. For more information refer &amp;ldquo;Technical discussion&amp;rdquo; of footing from help Content.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;2. For calculation of two way (punching) shear, footing self-weight is not added to axial load.&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;Concept of Footing punching shear criteria is column punches in the footing. Load from the column punches the column in footing. Self-weight of footing, overburden load do not participate in punching of column as it is a uniformly distributed load, thus it is not considered in design. For more information refer &amp;ldquo;Technical discussion&amp;rdquo; of footing from help Content.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;3. As per design, required reinforcement is 1478/1528 sqmm along L/B direction. Provided reinforcement is T12@175 mm which amounts to 1453 sqmm only for 2.25 m width of footing, whereas the calculation report shows Ast provided as 1583sqmm. Please clarify&lt;/strong&gt;.
&lt;ul&gt;
&lt;li&gt;Width = 2250 mm Ast required = 1478 sqmm Reinforcement provided = T12@175 mm In RCDC the number of bars required are calculated and spacing is calculated. While presenting the spacing rounded to 5 mm. In this example, number of bars as per spacing would be calculated as below &amp;ndash; (2250 / 175 = 12.86 which is 13 spaces). Hence number of bars would be 14. Thus actual Ast-provided would be (14x113.097 = 1584) 1584 sqmm which is more than required.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;4. Please clarify the footing type &amp;ldquo;on raft&amp;rdquo; given in RCDC&lt;/strong&gt;.
&lt;ul&gt;
&lt;li&gt;RCDC designs the isolated footings. The purpose of this options is to maintain the same thickness of first step for all footings if all footing are connected by common raft. This type of footing mostly use in the basement structures. The concept of this type of footing is similar to stepped footing.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;5. How is the volume of trapezoidal footing calculated in RCDC?&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;RCDC calculates the weight of trapezoidal footing as per following formulations, Self-wt. of footing Volume of footing = ((L*B*D) + ((((L*B) + (Lt*Bt))/2)*(D-d))/1000^3 Where, L= Length of footing B= Width of footing D= Depth of footing Lt= Length of footing top Bt= Width of footing top d= depth of sloping area.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;6.&lt;em&gt;In RCDC, the minimum rebar&amp;rsquo;s in Bottom are calculation based on effective Depth of the Foundation (Dff),whereas as per Clause 26.5.2.1 the minimum %Pt&amp;nbsp; is 0.12 of the Gross cross section area. Ast (minimum) as per IS456-200 Clause 26.5.2.1 is 0.12% of the Gross Cross section area.&lt;em&gt;Therefore,&amp;nbsp; for&amp;nbsp; F4 1800 x 1800 x 500 thk. : Ast mini = (0.12/100) x 500 x 1800 = 1080 Sqmm. &lt;em&gt;RCDC Calculations. Area calculation based on Deff. { (0.12/100) x 411 x 1800 = 887.76 Sqmm }. &lt;em&gt;Actually we end up providing less %Pt than required. &amp;lt; 1080 sqmm actual requirement vs 888 sqmm Provided&amp;gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;Please refer below snap extracted from IS 456,&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1598267093444v1.png" /&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Minimum reinforcement is for the total cross section area, thus 0.12% steel is to be provided at top and bottom.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;In your case, top reinforcement is selected and below is the reinforcement given,&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1598267129735v2.png" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;The minimum bottom reinforcement is given as 0.12% and top as 0.06%. Thus In your case, the RCDC will check the total reinforcement to be provided at a given cross section area as 0.12%. here, 0.06% is already provided at top, thus at bottom it will provided as per the 0.12% given by you with deff. Refer below snap of calculation &amp;nbsp;report.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/0410.jpg" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Now, don&amp;rsquo;t select the top reinforcement and maintain the same reinforcement, below is the output&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/3124.jpg" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Reinforcement is provided indirectly as 0.12% with total depth. 0.12 x 500 x 1800/100 = 1080 sqmm.&amp;nbsp; If we take Deff, then 0.141 x 427 x 1800/100 = 1083.72 sqmm. So the final reinforcement required is 1080 sqmm.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Here, the required pt has increased to match with the 0.12% with total D.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;If you want to reduce the Bottom reinforcement, please provide bottom reinforcement as 0.06%&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:30px;"&gt;&lt;strong&gt;7. &lt;em&gt;Can RCDC design the footings for If there is tension in the column due to lateral loads? &lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;Yes, RCDC can design the footing if column having tensile forces. User can design the footing with or without Loss of Contact options if there is tension in column OR one of the corners in footing is in tension.&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;Without loss of contact, RCDC will try to maintain the +ve pressure at all four corners of footing by increasing the self-weight. It is recommended to consider overburden to reduce the footing size in this case.&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;With loss of contact, RCDC will try to maintain the LOC within permissible limits and it will design the footing.&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;em&gt;It will also design and provide the top reinforcement if required in both the cases.&lt;/em&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;em&gt;&lt;/em&gt;&lt;/p&gt;
&lt;p style="padding-left:30px;"&gt;&lt;strong&gt;8.&lt;/strong&gt;&lt;em&gt;&lt;span&gt;&lt;strong&gt;Can We design Eccentric Footing in RCDC?&lt;/strong&gt; &lt;/span&gt;&lt;/em&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Yes, RCDC can design eccentric footing. Refer below link for more details,&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;Eccentric Footing Design&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;a href="/products/ram-staad/m/structural_analysis_and_design_gallery/274459"&gt;https://communities.bentley.com/products/ram-staad/m/structural_analysis_and_design_gallery/274459&lt;/a&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;/p&gt;
&lt;p style="padding-left:30px;"&gt;&lt;strong&gt;9. &lt;em&gt;What is Loss of contact? How RCDC perform the design of footing if LOC is selected?&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;RCDC allow user to provide permissible limits for the loss of contact. If in any case due to tension in footing or heavy lateral moments, corners of the footings experience the -ve pressure. -ve pressure could be at corner or one of the sides of footing. i.e. two adjacent corners with -ve pressure. Technically, maximum 50% LOC is allowed. Thus, maximum limit in RCDC for LOC is 50%. User can provide the % LOC as per its design requirements. If there is LOC, top reinforcement would be design as per the bending moment at top face of footing due to loss of contact.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;For more details, procedure and validation problems, please refer below link.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;Footing design with LOC&lt;/p&gt;
&lt;p style="padding-left:120px;"&gt;&lt;strong&gt;&lt;em&gt;&lt;a href="/products/ram-staad/m/structural_analysis_and_design_gallery/274312"&gt;https://communities.bentley.com/products/ram-staad/m/structural_analysis_and_design_gallery/274312&lt;/a&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:120px;"&gt;&lt;strong&gt;&lt;em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:30px;"&gt;&lt;strong&gt;&lt;em&gt;10.&lt;em&gt;&lt;span&gt;Can you explain the various options available for pressure calculation in RCDC footing design?&lt;/span&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;RCDC provides following options to calculate base pressure,&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;Average Pressure&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;Maximum Pressure&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;Factored SBC&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;Above options are explained below with example:&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;img src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1605350325737v2.png" alt=" " /&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;img src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1605350336098v3.png" alt=" " /&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;i&gt;&lt;em&gt;&lt;img src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1605350348030v4.png" alt=" " /&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/em&gt;&lt;/i&gt;&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p style="padding-left:30px;"&gt;&lt;/p&gt;
&lt;p style="padding-left:120px;"&gt;&lt;strong&gt;&lt;em&gt;&amp;nbsp;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;

&lt;div style="font-size: 90%;"&gt;Tags: loss of contact, footing, RCDC, Eccentric Footing Design&lt;/div&gt;
</description></item><item><title>RCDC-Footing</title><link>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing/revision/6</link><pubDate>Mon, 24 Aug 2020 11:09:46 GMT</pubDate><guid isPermaLink="false">6dad98f5-dbc9-4c4d-a9ba-e9da8dc6aa8e:b8d0de3a-5bef-41b5-b7fb-e6dff09549e5</guid><dc:creator>Abhijeet Gundaye</dc:creator><comments>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing#comments</comments><description>Revision 6 posted to RAM | STAAD | ADINA Wiki by Abhijeet Gundaye on 8/24/2020 11:09:46 AM&lt;br /&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;1. How the effective self-weight of the footing is calculated?&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;Effective self-weight of footing is calculated as additional load of footing volume with respect to difference in density of concrete and soil. For more information refer &amp;ldquo;Technical discussion&amp;rdquo; of footing from help Content.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;2. For calculation of two way (punching) shear, footing self-weight is not added to axial load.&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;Concept of Footing punching shear criteria is column punches in the footing. Load from the column punches the column in footing. Self-weight of footing, overburden load do not participate in punching of column as it is a uniformly distributed load, thus it is not considered in design. For more information refer &amp;ldquo;Technical discussion&amp;rdquo; of footing from help Content.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;3. As per design, required reinforcement is 1478/1528 sqmm along L/B direction. Provided reinforcement is T12@175 mm which amounts to 1453 sqmm only for 2.25 m width of footing, whereas the calculation report shows Ast provided as 1583sqmm. Please clarify&lt;/strong&gt;.
&lt;ul&gt;
&lt;li&gt;Width = 2250 mm Ast required = 1478 sqmm Reinforcement provided = T12@175 mm In RCDC the number of bars required are calculated and spacing is calculated. While presenting the spacing rounded to 5 mm. In this example, number of bars as per spacing would be calculated as below &amp;ndash; (2250 / 175 = 12.86 which is 13 spaces). Hence number of bars would be 14. Thus actual Ast-provided would be (14x113.097 = 1584) 1584 sqmm which is more than required.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;4. Please clarify the footing type &amp;ldquo;on raft&amp;rdquo; given in RCDC&lt;/strong&gt;.
&lt;ul&gt;
&lt;li&gt;RCDC designs the isolated footings. The purpose of this options is to maintain the same thickness of first step for all footings if all footing are connected by common raft. This type of footing mostly use in the basement structures. The concept of this type of footing is similar to stepped footing.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;5. How is the volume of trapezoidal footing calculated in RCDC?&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;RCDC calculates the weight of trapezoidal footing as per following formulations, Self-wt. of footing Volume of footing = ((L*B*D) + ((((L*B) + (Lt*Bt))/2)*(D-d))/1000^3 Where, L= Length of footing B= Width of footing D= Depth of footing Lt= Length of footing top Bt= Width of footing top d= depth of sloping area.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;6.&lt;em&gt;In RCDC, the minimum rebar&amp;rsquo;s in Bottom are calculation based on effective Depth of the Foundation (Dff),whereas as per Clause 26.5.2.1 the minimum %Pt&amp;nbsp; is 0.12 of the Gross cross section area. Ast (minimum) as per IS456-200 Clause 26.5.2.1 is 0.12% of the Gross Cross section area.&lt;em&gt;Therefore,&amp;nbsp; for&amp;nbsp; F4 1800 x 1800 x 500 thk. : Ast mini = (0.12/100) x 500 x 1800 = 1080 Sqmm. &lt;em&gt;RCDC Calculations. Area calculation based on Deff. { (0.12/100) x 411 x 1800 = 887.76 Sqmm }. &lt;em&gt;Actually we end up providing less %Pt than required. &amp;lt; 1080 sqmm actual requirement vs 888 sqmm Provided&amp;gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;Please refer below snap extracted from IS 456,&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1598267093444v1.png" /&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Minimum reinforcement is for the total cross section area, thus 0.12% steel is to be provided at top and bottom.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;In your case, top reinforcement is selected and below is the reinforcement given,&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1598267129735v2.png" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;The minimum bottom reinforcement is given as 0.12% and top as 0.06%. Thus In your case, the RCDC will check the total reinforcement to be provided at a given cross section area as 0.12%. here, 0.06% is already provided at top, thus at bottom it will provided as per the 0.12% given by you with deff. Refer below snap of calculation &amp;nbsp;report.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/0410.jpg" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Now, don&amp;rsquo;t select the top reinforcement and maintain the same reinforcement, below is the output&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/3124.jpg" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Reinforcement is provided indirectly as 0.12% with total depth. 0.12 x 500 x 1800/100 = 1080 sqmm.&amp;nbsp; If we take Deff, then 0.141 x 427 x 1800/100 = 1083.72 sqmm. So the final reinforcement required is 1080 sqmm.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Here, the required pt has increased to match with the 0.12% with total D.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;If you want to reduce the Bottom reinforcement, please provide bottom reinforcement as 0.06%&lt;/span&gt;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;

&lt;div style="font-size: 90%;"&gt;Tags: footing, RCDC&lt;/div&gt;
</description></item><item><title>RCDC-Footing</title><link>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing/revision/5</link><pubDate>Mon, 24 Aug 2020 11:06:23 GMT</pubDate><guid isPermaLink="false">6dad98f5-dbc9-4c4d-a9ba-e9da8dc6aa8e:b8d0de3a-5bef-41b5-b7fb-e6dff09549e5</guid><dc:creator>Abhijeet Gundaye</dc:creator><comments>https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/41956/rcdc-footing#comments</comments><description>Revision 5 posted to RAM | STAAD | ADINA Wiki by Abhijeet Gundaye on 8/24/2020 11:06:23 AM&lt;br /&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;1. How the effective self-weight of the footing is calculated?&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;Effective self-weight of footing is calculated as additional load of footing volume with respect to difference in density of concrete and soil. For more information refer &amp;ldquo;Technical discussion&amp;rdquo; of footing from help Content.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;2. For calculation of two way (punching) shear, footing self-weight is not added to axial load.&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;Concept of Footing punching shear criteria is column punches in the footing. Load from the column punches the column in footing. Self-weight of footing, overburden load do not participate in punching of column as it is a uniformly distributed load, thus it is not considered in design. For more information refer &amp;ldquo;Technical discussion&amp;rdquo; of footing from help Content.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;3. As per design, required reinforcement is 1478/1528 sqmm along L/B direction. Provided reinforcement is T12@175 mm which amounts to 1453 sqmm only for 2.25 m width of footing, whereas the calculation report shows Ast provided as 1583sqmm. Please clarify&lt;/strong&gt;.
&lt;ul&gt;
&lt;li&gt;Width = 2250 mm Ast required = 1478 sqmm Reinforcement provided = T12@175 mm In RCDC the number of bars required are calculated and spacing is calculated. While presenting the spacing rounded to 5 mm. In this example, number of bars as per spacing would be calculated as below &amp;ndash; (2250 / 175 = 12.86 which is 13 spaces). Hence number of bars would be 14. Thus actual Ast-provided would be (14x113.097 = 1584) 1584 sqmm which is more than required.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;4. Please clarify the footing type &amp;ldquo;on raft&amp;rdquo; given in RCDC&lt;/strong&gt;.
&lt;ul&gt;
&lt;li&gt;RCDC designs the isolated footings. The purpose of this options is to maintain the same thickness of first step for all footings if all footing are connected by common raft. This type of footing mostly use in the basement structures. The concept of this type of footing is similar to stepped footing.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;5. How is the volume of trapezoidal footing calculated in RCDC?&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;RCDC calculates the weight of trapezoidal footing as per following formulations, Self-wt. of footing Volume of footing = ((L*B*D) + ((((L*B) + (Lt*Bt))/2)*(D-d))/1000^3 Where, L= Length of footing B= Width of footing D= Depth of footing Lt= Length of footing top Bt= Width of footing top d= depth of sloping area.&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;6.&lt;em&gt;In RCDC, the minimum rebar&amp;rsquo;s in Bottom are calculation based on effective Depth of the Foundation (Dff),whereas as per Clause 26.5.2.1 the minimum %Pt&amp;nbsp; is 0.12 of the Gross cross section area. Ast (minimum) as per IS456-200 Clause 26.5.2.1 is 0.12% of the Gross Cross section area.&lt;em&gt;Therefore,&amp;nbsp; for&amp;nbsp; F4 1800 x 1800 x 500 thk. : Ast mini = (0.12/100) x 500 x 1800 = 1080 Sqmm. &lt;em&gt;RCDC Calculations. Area calculation based on Deff. { (0.12/100) x 411 x 1800 = 887.76 Sqmm }. &lt;em&gt;Actually we end up providing less %Pt than required. &amp;lt; 1080 sqmm actual requirement vs 888 sqmm Provided&amp;gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;Please refer below snap extracted from IS 456,&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/li&gt;
&lt;/ul&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;&lt;strong&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&lt;em&gt;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; &lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1598267093444v1.png" /&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Minimum reinforcement is for the total cross section area, thus 0.12% steel is to be provided at top and bottom.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;In your case, top reinforcement is selected and below is the reinforcement given,&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1598267129735v2.png" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;The minimum bottom reinforcement is given as 0.12% and top as 0.06%. Thus In your case, the RCDC will check the total reinforcement to be provided at a given cross section area as 0.12%. here, 0.06% is already provided at top, thus at bottom it will provided as per the 0.12% given by you with deff. Refer below snap of calculation &amp;nbsp;report.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " height="106" src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1598267159563v3.png" width="434" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Now, don&amp;rsquo;t select the top reinforcement and maintain the same reinforcement, below is the output&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;&lt;img alt=" " height="128" src="/resized-image/__size/320x240/__key/communityserver-wikis-components-files/00-00-00-00-54/pastedimage1598267179175v4.png" width="459" /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Reinforcement is provided indirectly as 0.12% with total depth. 0.12 x 500 x 1800/100 = 1080 sqmm.&amp;nbsp; If we take Deff, then 0.141 x 427 x 1800/100 = 1083.72 sqmm. So the final reinforcement required is 1080 sqmm.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;Here, the required pt has increased to match with the 0.12% with total D.&lt;/span&gt;&lt;/p&gt;
&lt;p style="padding-left:90px;"&gt;&lt;span&gt;If you want to reduce the Bottom reinforcement, please provide bottom reinforcement as 0.06%&lt;/span&gt;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;

&lt;div style="font-size: 90%;"&gt;Tags: footing, RCDC&lt;/div&gt;
</description></item></channel></rss>