Expert: Babak Esmailzadeh Hakimi - 1/28/2012

Question
dear sir,
1.I am designing pile cap for a lift core of a 8 storied building of 90 feet height.But I am in a fix for designing this because here is no column but three shear wall for making the core of the lift.Please help me in understanding the problem and if there is any reference please mention.
2.if I want to place the lift core on a mat foundation what will be the situation.

Answer
Dear Barek

I cant understand why you want a pile system for a lift core, because usually the loading of lifts are not so serious unless you have a very bad soil situation or essentially you want it for your shear walls not for your lift. However you can arrange your pile group at a level somehow lower than your mat basement and to have a cap hugging all piles and shear wall basement. So your mat problem will be resolved at the same time.

You can use the shear walls as a good set of support for your lift framing (core). You may fix steel profiles along the height of shear walls.

Hope being satisfactory , if not give me back some extra information , to help me to understand better your situation.

Regards
Babak E Hakimi