Reinforcement detailing of Columns from ETABS output
AIM:-
- To provide the details of longitudinal reinforcement for the two columns (3A & 3B), from foundation to terrace level
Introduction :-
- The factored axial compression stress considered all load combination relating to sesimic loads shall be
limited to 0.40 fck in all column .
- The Minimum Column Dimension as per IS 13290-2016 = 20 db
wherer db = Max beam bar diameter
- In column cracking will be much less as compared to beam because large amount of axial force is present
Procedure: -
Step 1)
- Open the Challenge 7 Etabs file which we have downloaded for Beam Design.
Step 2)
- Select the Two columns And so select object only.
- Go to the 3D view
- Go to the Run Analysis
- simply presse the Concrete Frame Desgin
Step 3)
- Then Go to the elevetion view
- Elevation View A
- Thane Apply 3 elevation view
Step 4)
Longitudinal Reinforcement
Step 5)
- Then Go to theApply Shear Reinforcement
- Than go to the edit story to all floor in detailed
Step 6)
i) Now we have to provide detail reinforcement for Column
1) For GRID 3A -
1) From Base to Terrace floor the maximum Ast is = 7027
2) So we can provide 12nos of 28mm dia bar = 12 x 616
= 7392mm^2
ii) Details are shown below -
2) For GRID 3B -
1) From Base to Terrace floor the maximum Ast = 5046 mm^2
2) So , Provide 8 bars of 25 mm diameter for the column = 8 x 490.87*8
= 3927mm2
3) Provide 4 bars of 20 mm diameter for the column = 4 x 314.16
= 1256.64mm2
4) Total = 3927 + 1257
= 5180 mm^2
5) Details are shown below
Step 7)
Typical Beam column Joint as per special confining reinforcement provision of clause 8.1 of IS 13920 - 2016 -
i) As per IS 13920 - 2016 at beam column junction -
For beam - The spacing from the face of the beam should not be more than 100 mm till 2d
For Column - The spacing from the face of the column will be lo and should not be more than
= Least lateral dimension
= 16)th16)�ℎ) of clear span
= 450 mm
Result -
ii) Shear reinforcement & lapping details as per special confining reinforcement provision
of clause 8.1 of IS 13920 - 2016.
1) For Io - Not Less Than
i) Larger Column Dimension - 650mm
ii) 1/6 )^(th`) of clear span of column - 560mm
iii) 450 mm
So Adopt 650 mm
2) Confinement Spacing Not more than
i) 1/4 th of smaller column dimension = 113 mm
ii) 6 times of dia of column main bar - 168 mm
iii) 100 mm
So we have to adopt 100 mm