Pile cap in Two Pours
Pile cap in Two Pours
(OP)
Folks,
I have a situation with a pile cap supporting a basement slab. I have attached the proposed construction sequence.
I am concerned about punching shear especially with the two pours. I will have tie-in reinforcing between the pours and extend the reinforcing from the piles and hook into the 500mm slab.
Thoughts/Suggestions?
I have a situation with a pile cap supporting a basement slab. I have attached the proposed construction sequence.
I am concerned about punching shear especially with the two pours. I will have tie-in reinforcing between the pours and extend the reinforcing from the piles and hook into the 500mm slab.
Thoughts/Suggestions?






RE: Pile cap in Two Pours
If you are going to do it as 2 stages then you might as well do it as separate pile cap and ground slab with a bond breaker between and compressible material around the columns.
RE: Pile cap in Two Pours
RE: Pile cap in Two Pours
RE: Pile cap in Two Pours
understand now.
The horizontal shear on the pour joint will be proportionate to the punching shear stress.
I would definately suggest a tamped surface to help with the friction.
RE: Pile cap in Two Pours
What is missing from your sketch is the mud slab for installing the waterproofing. After that goes in, I would use fibre cement sheets to protect the waterproofing during construction of the slab.
RE: Pile cap in Two Pours
RE: Pile cap in Two Pours
RE: Pile cap in Two Pours
RE: Pile cap in Two Pours
RE: Pile cap in Two Pours
RE: Pile cap in Two Pours
Find the angle of your compression strut from horizontal = theta, and the compression force, F.
The shear in the slip plane due to the compression strut, V,req'd = F Cos Theta for each compression strut.
Provide shear friction reinforcement to compensate for this shear such that Vreqd <= phi Avf Fy mu
Note that in a perfect world these shears will cancel each other but I'd be tempted to ignore the cancelling effect in order to compensate for any local shear bending requirements ( the VQ/I requirements for instance).
RE: Pile cap in Two Pours