Concrete Shear/Bearing at Pile-to-Slab Interface

[mikeCTE]

We are designing a pile supported slab that supports a building structure. The columns from the building sit directly above where the piles are with a 12" slab between to two elements.

In timber design, for shear, you can ignore loads placed within "d" of the support, where "d" is the depth of your beam.

Is there a similar provision in concrete design (ACI)? To me, it feels like direct bearing between the column base plate and pile below. By doing this, it would allow us to skip stirrups in this area (30% of load at pile is from building, 70% from self weight of slab and slab live load).

Thanks

 

[KootK]

Yes, there is a similar provision in concrete. Probably more so than in wood really.

What are the dimensions of your base plates?

What's the diameter of your piles?

HELP! I'd like your help with a thread that I was forced to move to the business issues section where it will surely be seen by next to nobody that matters to me:

http://www.eng-tips.com/viewthread.cfm?qid=456235

 

[calvinandhobbes10]

I would sure consider thickening the mat locally at each pile head. Avoids the stirrups, as you were trying to do, and also provides easy, definite punching shear resistance for that High slab load bearing on the skinny Pile.

I agree about the column load being so close to the pile. Check bearing (easy), Make sure any complications due to pile installation tolerance will not cause problems.