Check for transfer forces at column base (pad and strip base:ACI 318)

Tekla Structural Designer
2021
Tekla Structural Designer

Check for transfer forces at column base (pad and strip base:ACI 318)

This check applies when a concrete column is attached to the foundation.

Determinate the bearing strength of the column:

Φ*Pnb,c
  =  
Φbearing (0.85*f’c * Ac)
If
Φ*Pnb,c
  <  
- Pu
Then check fails
Else determinate the bearing strength of the footing:
Φ*Pnb,f
  =  
min [√(A2/Ac), 2] * Φbearing (0.85*f’c * Ac)
where for rectangular columns:
A2
  =  
min {Lx , 2tftg + lx+ min [(Lx-lx)/2 - abs(ex), 2tftg]} * min {Ly , 2tftg + ly + min [(Ly-ly)/2 - abs(ey), 2tftg]}
Note:

Circular columns are treated as square members with the same area.

If
Φ*Pnb,f
  <  
- Pu
Then check fails
Required min. area of dowel bars between column and footing is then:1
As,min
  =  
0.005*Ac
Currently dowel bars are not designed.
The area of the provided column reinforcement As,prov,column is the same as the provided reinforcement of starter/dowel bars.
If
As,min
  >  
As,prov,column
Then check fails
1 ACI 318-08 Section 15.8.2.1
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