Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

RE: Lateral Resistance for Structured Pile Supported Foundation

[Subject Prev][Subject Next][Thread Prev][Thread Next]

The lateral force has to be resisted somewhere, usually through passive in the pile caps and grade beams.  We have used batter piles, though no one likes installing them.  If no provisions are made other than the lateral resistance provided by the piles, then the piles have to have the appropriate capacity (15 kips).  It is pretty easy to obtain adequate passive in most cases.

 


From: Stuart, Matthew [mailto:mstuart(--nospam--at)schoordepalma.com]
Sent: Wednesday, May 30, 2007 4:33 AM
To: seaint(--nospam--at)seaint.org
Subject: Lateral Resistance for Structured Pile Supported Foundation

 

I have conducted a peer review of a structured (one-way slab and grade beam) pile supported foundation design. The building is considered an emergency shelter under the IBC and is subject to a considerable seismic base shear. The total lateral load required per pile is 15 kips. The geotechnical engineer has indicated that the vertical piles are good for about 1 to 2 kips of lateral capacity. We have recommended that (since the foundation is already constructed) structural fill be placed next to the grade beams to provide enough passive resistance against the seismic base shear. The design engineer is of the opinion that as long as the piles remain adequately braced by the underlying soils during an earthquake that there is no need to provide lateral resistance for the base shear. I am not aware of any Code or design provisions that allow one to ignore the load path mechanism and not provide some form of lateral resistance (either via battered piles, passive soil resistance or vertical pile lateral resistance) against applied forces. Anyone interested in providing some input concerning this issue?

 

D. Matthew Stuart, P.E., S.E., F.ASCE, SECB

Senior Project Manager

Structural Department

Associate

Schoor DePalma Engineers and Consultants

200 State Highway Nine

Manalapan, NJ 07726

732-577-9000 (Ext. 1283)

908-309-8657 (Cell)

732-298-9441 (Fax)

mstuart(--nospam--at)schoordepalma.com