Soil Subgrade Modulus
Soil Subgrade Modulus
(OP)
We are trying to determine the modulus of a soil subgrade underneath a concrete slab in an existing structure.
We are cutting a 3' x 3' square hole in the slab to access subgrade.
What would be the most cost-effective way to determine this?
We are cutting a 3' x 3' square hole in the slab to access subgrade.
What would be the most cost-effective way to determine this?





RE: Soil Subgrade Modulus
Given a reasonable soil classification, you should be able to estimate the modulus with enough accuracy that it won't make a big difference in your slab thickness calcs.
If you want to test for it, use a plate load test and cycle the load.
RE: Soil Subgrade Modulus
RE: Soil Subgrade Modulus
RE: Soil Subgrade Modulus
RE: Soil Subgrade Modulus
You can take a field density test of the existing subgrade.
You can take a bulk sample and pound a proctor.
You can remold to the percent compaction and do a soaked CBR.
You can correlate soaked CBR to subgrade modulus.
Other than the 10 days for the proctor/cbr it's pretty straightforward, but somewhat empirical.
f-d
¡papá gordo ain't no madre flaca!
RE: Soil Subgrade Modulus
hey, do any of you gents have the 1955 Geotechnique paper by Terzaghi on the topic? I've been looking around and can't find a copy. I looked for it a while back and got sidetracked...would like to read it since it's referenced in so many places.