Soil bearing capacity vs Subgrade Modulus
Soil bearing capacity vs Subgrade Modulus
(OP)
dear all,
i know the question might be funny, but i am quite confuse in designing a footing (e.g. isolated/spread footing). Some programs only consider the soil's sub-grade modulus(SAFE) and some the soil bearing capacity(STAAD).
Which is really more critical?
i know the question might be funny, but i am quite confuse in designing a footing (e.g. isolated/spread footing). Some programs only consider the soil's sub-grade modulus(SAFE) and some the soil bearing capacity(STAAD).
Which is really more critical?





RE: Soil bearing capacity vs Subgrade Modulus
So, you may say, well, the subgrade modulus models this "spring-like" behavior. Not really. Subgrade modulus really considers the structure's response to the subgrade support. It really doesn't get into the details of the soils below the depth of a foot or so.
Bearing pressure (ultimate) is important, but settlement usually governs allowable bearing pressure. Unless, that is, the engineer is just guessing. . .
f-d
¡papá gordo ain't no madre flaca!
RE: Soil bearing capacity vs Subgrade Modulus
With all due respect, this is a very basic question that should be asked to one of your (hopefully) senior colleagues.
You should not need a program to do this. Usually, the ultimate or allowable bearing pressure should be provided by the soils engineer, and you can use this to design a spread footing.
tg
RE: Soil bearing capacity vs Subgrade Modulus
If however, your geotechnical report states allowable bearing capacity, then you enter qallowable, which already considered settlement effects. This is probably what STAAD is asking you to input.
If you have gravity loads and a uniaxial moment, the allowable bearing capacity from the geotechnical report will suffice. If however, you had a biaxial moment, shear and vertical load and wanted the stresses induced on all corners to check for uplift, then the beam on elastic foundation method will be more accurate.
www.FoundEng.com
RE: Soil bearing capacity vs Subgrade Modulus
Thanks fattdad and fixedearth for the clarifications, it did really help.
Re: Trainguy:
Yeah you are absolutely right, but almost all of my senior colleagues are way out of reach.
Thanks and Regards.