

Project Name  :  a 
Client Name  :  a 
Engineer Name  :  a 
Design File  :  D:\Scube\000 RCDC 2010\10.0.0\Queries\Surendra Rao\RCDCStaadDemo with RCC wallColumn3.R3.rcdx 
Analysis File  :  D:\Scube\000 RCDC 2010\10.0.0\Standard model for Demo\Staad\RCDCStaadDemo with RCC wall.std 
Analysis Last Modified  :  12/31/2019 3:19:44 PM 
Definitions Of Terms:  
All forces in units kN and m  
All reinforcement details like area, spacing are mm  
Grade Of steel for 6 mm dia. bars is Fe250. It is irrespective of the grade of steel defined by user in column design.  
Neutral axis angle for resultant design moment is with respect to local major axis.  
1  β  =  Stiffness proportion factor at joint ( column stiffness/sum of stiffness of all members connected at joint) 
2  Δu  =  Elastically computed first order lateral deflection.(Relative deflections) 
3  ε1  =  Strain at level considered, Calculated ignoring the stiffening of the concrete in tension zone 
4  εm  =  Average steel strain at level considered 
5  acr  =  Distance from the point considered to the surface of the nearest longitudinal bar 
6  Ag  =  Gross area of the column cross section 
7  Ak  =  Area of confined concrete core 
8  Ash  =  Area of link cross section 
9  b  =  Effective Width of Column in mm 
10  B  =  Width / Smaller Dimension of Column in mm 
11  d  =  Effective Depth of Column in mm 
12  D  =  Depth / Larger Dimension of Column OR Diameter of Circular Column in mm 
13  Dk  =  Diameter Of core measured to the outside of circular link 
14  Ec  =  Modulus of elasticity of concrete 
15  Es  =  Modulus of elasticity of steel 
16  FcPerm  =  Permissible Stress in Concrete required in N/ (sqmm) 
17  Fst  =  Stress in steel 
18  FstPerm  =  Permissible Stress in Steel required in N/ (sqmm) 
19  Fck  =  Characteristic compressive strength of concrete cube in N/sqmm 
20  Fy  =  Yield Stress Of Steel in N/sqmm 
21  h  =  Longer dimension of rectangular link measured to its outer face 
22  Hu  =  Total lateral force acting within the story(Story shear) 
23  Hs  =  Height of the story (Floor height) 
24  k  =  Reduction factor for slenderness moments 
25  Max  =  Additional moment due to slenderness about major axis (Along D) 
26  May  =  Additional moment due to slenderness about minor axis (Along B) 
27  Mminx  =  Moment due to minimum eccentricity along D 
28  Mminy  =  Moment due to minimum eccentricity along B 
29  Muv  =  Moment capacity of web portion of wall as per clause 9.4.2 and Annes A of IS 13920  2016 
30  Mux  =  Factored moment Along D (Momemt About Major Axis) 
31  Muy  =  Factored moment Along B (Momemt About Minor Axis) 
32  MCap  =  Moment capacity of section for NA angle at design Pu 
33  MRes  =  Resultant design moment at angle to local major axis 
34  Pb  =  Axial capacity of column as defined in 39.7.1.1 
35  Pu  =  Factored axial force 
36  Pu_Total  =  Sum of Axial loads on all column in the story (Gravity Load) 
37  Q  =  Stability Index (factor for checking sway/ non sway condition for a given story) 
38  S  =  Link Spacing 
39  Shear Strength Enhancement Factor  =  Multiplying factor for shear strength of concrete as per 40.2.2 
40  Vur  =  Factored resultant shear force acting on the column 
41  Vux  =  Factored shear force Along B 
42  Vuy  =  Factored shear force Along D 
43  Wcr  =  Surface Crack Width 
44  WcrPerm  =  Permissible Crack Width required in mm 
45  β  =  It is a Neutral Axis angle corresponding to load angle to find out MCap 
Code References:  
IS 456  
ELEMENT  CLAUSE / table  
1  Max area of reinforcement  :  26.5.3.1a & b 
2  Min area of reinforcement  :  26.5.3.1a & b 
3  Min number of bars  :  26.5.3.1c 
4  Minimum Eccentricity Calc  :  25.4 & 39.2 
5  Effective Length  :  25.2 
6  Slenderness Moments  :  25.3 & 39.7 
7  Design for axial loads  :  39.3 
8  Design for axial loads And uniaxial bending  :  39.5 
9  Design for axial loads And Biaxial bending  :  39.6 
10  Design of horizontal links  :  26.5.3.2 
11  Design shear strength  :  40.2 
12  Stiffness Proportion Factor, β  :  E1 
13  Stability(Index, Q)  :  E 2 
14  Crack width calculation  :  3.8 
15  Multiplying factor to Beam Stiffness for effective length calculation  :  SP 24 1983 APPENDIX D 
IS 13920  2016  
ELEMENT  CLAUSE / table  
1  Spacing of special confining reinforcement  :  10.4 and 7.6 
2  C/s area of special confining reinforcement  :  7.6.1 
3  Applicability of boundary element  :  10.4.1 
4  MuvMoment Capacity of Web  :  Annex 
5  Additional Compressive Force in BE  :  10.4.2 
6  Check for BE in tension and compression  :  10.4.2.1 and 10.4.3 
7  Shear include due to Beam  :  7.5 
8  Minimum Flexural Strength of Column  :  7.2 
9  Shear Check at Column Joint  :  9.1 
10  Length of wall to thickness ratio  :  10.1.3 
11  Type of wall & Minimum reinforcement  :  10.1.4 
12  Largest diameter of longitudinal steel bar  :  10.1.8 
13  Shear reinforcement in RC wall  :  10.2.3 
14  Special confinement reinforcement in Boundary Element  :  10.4.4 
15  Minimum vertical reinforcement across horizontal construction joint  :  10.7 
Sway Calculation (Stability Index) 
For GlobalX Direction 
Level  Load Name  Storey Height (m)  Gravity Load P (kN)  Relative Displacements (mm)  Storey Shear (kN)  Stability Index  Sway Condition 
A  B  C  D  B x C / (A x D)  
0m to 4.2m  LOAD 3: LOAD CASE 3 EQX  4.2  58606.007  1.143  1754.701  0.009  Non Sway 
4.2m to 7.858m  LOAD 3: LOAD CASE 3 EQX  3.658  51337.009  1.39  1690.676  0.012  Non Sway 
7.858m to 12.058m  LOAD 3: LOAD CASE 3 EQX  4.2  31804.197  1.704  1450.58  0.009  Non Sway 
12.058m to 16.258m  LOAD 3: LOAD CASE 3 EQX  4.2  13878.005  1.317  1015.406  0.004  Non Sway 
For GlobalY Direction 
Level  Load Name  Storey Height (m)  Gravity Load P (kN)  Relative Displacements (mm)  Storey Shear (kN)  Stability Index  Sway Condition 
A  B  C  D  B x C / (A x D)  
0m to 4.2m  LOAD 4: LOAD CASE 4 EQY  4.2  58606.007  0.949  1754.701  0.008  Non Sway 
4.2m to 7.858m  LOAD 4: LOAD CASE 4 EQY  3.658  51337.009  1.254  1690.676  0.01  Non Sway 
7.858m to 12.058m  LOAD 4: LOAD CASE 4 EQY  4.2  31804.197  1.635  1450.58  0.009  Non Sway 
12.058m to 16.258m  LOAD 4: LOAD CASE 4 EQY  4.2  13878.005  1.402  1015.406  0.005  Non Sway 
General Data  
Column No.  :  C1  
Level  :  0m To 4.2m  
Frame Type  =  NonDuctile  
Response Reduction Factor  =  3  
Design Code  =  IS 456 + IS 13920  2016  
Grade Of Concrete  =  M25  N/sqmm 
Grade Of Steel  =  Fe415  N/sqmm 
Column B  =  700  mm 
Column D  =  700  mm 
Clear Floor Height @ B  =  3400  mm 
Clear Floor Height @ D  =  3400  mm 
No Of Floors  =  1  
No Of Columns In Group  =  1  
Column Type  :  Braced  
Minimum eccentricity check  :  One Axis at a Time  
Code defined D/B ratio  :  4  
D/B Ratio  :  1 <= 4 Hence, Design as Column  
Flexural Design (Analysis Forces)  
Analysis Reference No.  =  1  
Load Combination  =  [12] : 0.9 (LOAD 1: LOAD CASE 1) +1.5 (LOAD 4: LOAD CASE 4 EQY)  
Critical Location  =  Bottom Joint  
Put (top joint)  =  228.72  kN  
Muxt (top joint)  =  35.97  kNm  
Muyt (top joint)  =  65.96  kNm  
Vuxt (top joint)  =  64.73  kN  
Vuyt (top joint)  =  15.25  kN  
Pub (bottom joint)  =  275.04  kN  
Muxb (bottom joint)  =  28.06  kNm  
Muyb (bottom joint)  =  205.81  kNm  
Vuxb (bottom joint)  =  64.73  kN  
Vuyb (bottom joint)  =  15.25  kN 
Effective Length Calculation 
Calculation Along Major Axis Of Column 
Joint  Column Stiffness  Beam Sizes  Beam Stiffness  Beta  
Beam 1 (Length x Width x Depth) 
Beam 2 (Length x Width x Depth) 
Beam 1  Beam 2  
N/m  mm  mm  N/m  N/m  
Bottom  476.389  No Beam  No Beam      1 
Top  476.389  8000 x 400 x 800  No Beam  213.333    0.827 
Sway Condition (as per Stability Index)  =  Non Sway  
Effective Length Factor along Major Axis  =  0.93 
Calculation Along Minor Axis Of Column 
Joint  Column Stiffness  Beta  
Beam 1 (Length x Width x Depth) 
Beam 2 (Length x Width x Depth) 
Beam 1  Beam 2  
N/m  mm  mm  N/m  N/m  
Bottom  476.389  No Beam  No Beam      1 
Top  476.389  5710 x 400 x 800  No Beam  298.891    0.774 
Sway Condition (as per Stability Index)  =  Non Sway  
Effective Length Factor along Minor axis  =  0.92 
Minimum Eccentricity Check  
Since Axial Force is compressive, Min. Eccentricity check to be performed  
Most critical case is with Min. Eccentricity check in Xdirection  
Minimum Eccentricity Along D:  
Minimum Eccentricity  =  Unsupported Length / 500 + D / 30  
=  30.13  mm  
Minimum Eccentricity  >  20  mm 
Mminx (top)  =  Pu x Minimum Eccentricity  
=  6.89  kNm  
Mminx (bottom)  =  Pu x Minimum Eccentricity  
=  8.29  kNm  
Slenderness Check  
Max Slenderness Ratio(L/B)  =  4.86  
<  60  (Hence Ok)  
Column Is Braced Along D  
Slenderness Check Along D:  
Effective Length Factor  =  0.93  
Slenderness Ratio  =  Effective Length / D  
=  4.52, Column not Slender Along D  
Column Is Braced Along B  
Slenderness Check Along B:  
Effective Length Factor  =  0.92  
Slenderness Ratio  =  Effective Length / B  
=  4.47, Column not Slender Along B  
Calculation of Design Moment 
Direction  Manalysis  Mmin (Abs)  Mdesign  Minit  Mslndx (Abs)  Mdesignfinal 
A  B  C  D  E  F  
Major Axis Mux (top)  35.97  6.89  35.97    0  35.97 
Major Axis Mux (bottom)  28.06  8.29  28.06    0  28.06 
Minor Axis Muy (top)  65.96    65.96    0  65.96 
Minor Axis Muy (bottom)  205.81    205.81    0  205.81 
Where  
A  =  Moments directly from analysis 
B  =  Moments due to minimum eccentricity 
C  =  Maximum of analysis moment and min. eccentricity = Max (A,B) 
D  =  Initial moment = 0.4 x Min (top, bottom) ± 0.6 x Max (top, bottom) [As per sign requirement] 
E  =  Moment due to slenderness effect 
F  =  Final design Moment = Max(C Top Bottom , D Top Bottom) + E 
Final Critical Design Forces  
Pu  =  275.04  kN 
Mux  =  28.06  kNm 
Muy  =  205.81  kNm 
Resultant Moment (Combined Action)  
Moment Capacity Check  
Pt Calculated  =  0.46  
Reinforcement Provided  =  20T12  
Load Angle  =  Tan^{1}(Muy/Mux)  
=  82.24  deg  
MRes  =  207.72  kNm 
MCap  =  325.91  kNm 
Capacity Ratio  =  MRes/ MCap  
=  0.64 <= 1  
Shear Design (Analysis Forces)  
Design for shear along D  
Critical Load Combination  =  [11] : 0.9 (LOAD 1: LOAD CASE 1) 1.5 (LOAD 3: LOAD CASE 3 EQX)  
Design shear force, Vuy  =  73.9613  kN  
Pu  =  435  kN  
Deff  =  644  mm  
Design shear stress, Tvy  =  Vuy / (Bx Deff)  N/sqmm  
=  0.1641  N/sqmm  
Pt  =  0.231  %  
Design shear strength, Tc  =  0.3523  N/sqmm  
Shear Strength Enhancement Factor  =  1 + 3 x Pu / ( B x D x Fck)  
=  1.1065  
Shear Strength Enhancement Factor (max)  =  1.5  
Shear Strength Enhancement Factor  =  1.1065  
Enhanced shear strength, Tce  =  0.3898  N/sqmm  
Design shear check  =  Tvy < Tc x Enhancement factor  
Link for Shear Design along D are not required  
Design for shear along B  
Critical Load Combination  =  [13] : 0.9 (LOAD 1: LOAD CASE 1) 1.5 (LOAD 4: LOAD CASE 4 EQY)  
Design shear force, Vux  =  81.8265  kN  
Pu  =  495.49  kN  
Beff  =  644  mm  
Design shear stress, Tvx  =  Vux / (D x Beff)  kN  
=  0.1815  N/sqmm  
Pt  =  0.231  %  
Design shear strength, Tc  =  0.3523  N/sqmm  
Shear Strength Enhancement Factor  =  1 + 3 x Pu / (B x D x Fck)  
=  1.1213  
Shear Strength Enhancement Factor (max)  =  1.5  
Shear Strength Enhancement Factor  =  1.1213  
Enhanced shear strength, Tce  =  0.395  N/sqmm  
Design shear check  =  Tvx < Tc x Enhancement factor  
Link for Shear Design along B are not required 
Design Of Links  
Links in the zone where special confining links are not required  
Normal Links  
Diameter of link  =  8  mm  
>  Max. longitudinal bar dia / 4  
=  3  mm  
Criterion for spacing of normal links  
Min. Longitudinal Bar dia X 16  =  192  mm  
Min. dimension of column  =  700  mm  
Max. 300 mm  =  300  mm  
Provided spacing  =  175  mm  
Table For Links 
Required  Provided  
Normal Design  Shear Design  Ductile Design  Normal Zone  Ductile Zone  
Link Dia.  8      8   
Spacing  175      175   