Check for transfer of horizontal forces by shear friction (pad and strip base:ACI 318)
This check applies when a concrete column is attached to the foundation.
Determinate if the shear-friction design method applicable1:
When surface is not intentionally roughened (conservative assumption)
| If | Vu ≤ Φshear * Ac min(0.2*f’c , 800psi) | for US units |
| Vu ≤ Φshear * Ac min(0.2*f’c , 5.5MPa) | for metric units | |
| where | ||
| Vu = max[abs(Fy,sup,u) , abs(Fx,sup,u)] |
Then maximum shear transfer is permitted at the base of the column.
Required area of dowel reinforcement:
| Avf |
|
Vu / (fy * Φshear*μ) |
where
μ = 0.6 when concrete not intentionally roughened (assumption)
μ = 1.0 when concrete intentionally roughened
μ = 1.4 when concrete placed monolithically
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
| Avf |
|
As,prov,column |
Then check fails
1 ACI 318-08 Section
15.8.2.1