No Pile cap needed below column
No Pile cap needed below column
(OP)
Hi Guys
Simple question:
I have 1000diameter piles supporting a 300mm suspended ground slab and 350square columns directly ontop of pile.
Am I right to think that no pile cap is needed if the pile will not punch through the slab?
Do I treat the pile basically as a column and check direct/face shear and punching shear. If not a problem to thickening needed. So basically whether there is a column on top of the slab or not makes no difference to whether I need a thickening or pile cap, its all goverened by the possibility of the pile punching through the slab.
Of course if the pile is of a small diameter, there is a good chance I might need a thickening.
Cheers
Simple question:
I have 1000diameter piles supporting a 300mm suspended ground slab and 350square columns directly ontop of pile.
Am I right to think that no pile cap is needed if the pile will not punch through the slab?
Do I treat the pile basically as a column and check direct/face shear and punching shear. If not a problem to thickening needed. So basically whether there is a column on top of the slab or not makes no difference to whether I need a thickening or pile cap, its all goverened by the possibility of the pile punching through the slab.
Of course if the pile is of a small diameter, there is a good chance I might need a thickening.
Cheers






RE: No Pile cap needed below column
RE: No Pile cap needed below column
BA
RE: No Pile cap needed below column
* bending in the slab (this assumes multiple piles are being used to support the column, which may not be the case)
* one way shear in the slab (probably won't control)
DaveAtkins
RE: No Pile cap needed below column
So the question would be refered to the ensured general stabilty of the building-structure-soil interaction, to be analyzed in the usual ways, i.e., for your problem, would not having some pile cap, or some pilecap restriction to displacement mean something that makes the foundation not work? If everything works, you know you have a sound foundation.
RE: No Pile cap needed below column
You bring up a valid point. If the column is not lined up with the centroid of the pile, then the induced moment will find its way into the slab based on joint stiffness. The slab will then have to be designed to take its share of moment.
I am not sure if you are in seismic country. If you are then you are required to tie your foundations together.
RE: No Pile cap needed below column
RE: No Pile cap needed below column
Michael.
Timing has a lot to do with the outcome of a rain dance.
RE: No Pile cap needed below column
The presence or not of an isolated cap on that pile will hardly make any difference, as long as slab punching is not an issue.
RE: No Pile cap needed below column