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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/" xmlns:slash="http://purl.org/rss/1.0/modules/slash/" xmlns:wfw="http://wellformedweb.org/CommentAPI/"><channel><title>Fundamental time period of bridge pier</title><link>https://communities.bentley.com/products/ram-staad/f/ram-staad-forum/222719/fundamental-time-period-of-bridge-pier</link><description>I want to calculate fundamental time period (eigen value method, using command MODAL CALCULATION REQUESTED) of bridge pier in staad pro using lumped mass in long &amp;amp; Trans direction as per IRC 6 &amp;amp; IRC SP 114. 
 I am enclosing the details . I think there</description><dc:language>en-US</dc:language><generator>Telligent Community 12</generator><item><title>RE: Fundamental time period of bridge pier</title><link>https://communities.bentley.com/thread/685157?ContentTypeID=1</link><pubDate>Wed, 01 Dec 2021 21:41:20 GMT</pubDate><guid isPermaLink="false">6dad98f5-dbc9-4c4d-a9ba-e9da8dc6aa8e:b61c3419-c7c5-48fc-9ff3-d6aa677d1178</guid><dc:creator>Seth Guthrie</dc:creator><description>&lt;p&gt;I don&amp;#39;t know how to advise you on this. This model is of the pier, but a spring at the top is presumably there to simulate the resistance of the bridge deck. The spring is fairly stiff in both lateral directions relative to the applied horizontal force (and mass) which is at the same node location. As such the significance of that point mass will be significantly reduced, and the structure period will be dominated by the self-weight of the remaining parts. The modal results that you get will be very sensitive to the stiffness of that spring.&amp;nbsp;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item></channel></rss>