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Re: Need default passive pressure in Santa Monica

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Dennis -

Without a soils report, we typically use 1000 psf bearing and 100 psf passive,
which can be doubled for isolated pole footings and increased by 1.33 for
seismic loads.  Occassionally, I try to use 150 or 200, but then the plan
checker usually asks for justification, i.e. a soils report.

For your case, I'd start with 100 psf.  When the owner complains how deep the
footings are, you can run out options at 200 psf, 300 psf, etc., to see the
effect on the footings depths and to determine whether the cost of the soils
report is justified.  If you only have a few footings, it is probably faster
and cheaper just to dig them deeper based on the 100 psf valules.

Bruce Resnick, SE
Parker Resnick Str. Eng.