Group Pile & Cap Bearing

[Jean_Wong]

Good Day!

I was assigned to determine the bearing capacity for a group of drilled shaft/bored piles. I used AASHTO LRFD 2012 as basis for my design. The cap would be 5m x 5m with 4 to 5 piles of 1m diameter. The cap thickness would be 1m to 2m.

Is it correct that I based my reduction factor for piles on the least center to center dimension with respect to pile diameter?

What are good references when I want to consider the cap bearing capacity?

How will I consider the cap bearing capacity?

Also what are the parameters I need in order to determine the load that the cap will carry?

Thanks!

 

[MotorCity]

The reduction in efficiency of a pile group is based on pile spacing, not pile diameter.

Bearing capacity of the cap is based on the allowable concrete bearing stress where the pile is supported by the cap.

Check one way shear, punching shear and flexure of the cap spanning over the piles.