Calculate Allowable Soil Bearing Pressure
Calculate Allowable Soil Bearing Pressure
(OP)
I have an existing condition of 4" of unreienforced concrete on top of a sandy soil that has been in place for 10-15 years. I am looking to have the 4" of concrete support a point load and need to find the allowable Soil bearing pressure in order to give the structural engineer the starting point for the load calculations. I have a recent AAShto T-180 Method A soil analysis, ASTM C136 Sieve Analysis and a AASHTO T193 CBR Test....how do I calculate the allowable soil bearing pressure for the subgrade...???





RE: Calculate Allowable Soil Bearing Pressure
RE: Calculate Allowable Soil Bearing Pressure
ok, couldn't resist, sorry.. you're going to need other info than those listed. if you have any geotech/CMT companies that are looking to market themselves to you or your client, you should find their pricing reasonable, especially if you're talking about placing racks on an industrial slab (random guess). you should have an idea on the magnitude of the loads and acceptable level of settlement when discussing it.
The lower the bearing pressure the structural egr needs while still keeping the design efficient, the easier it will be for Geot Egr to limit frequency (cost) of testing.
RE: Calculate Allowable Soil Bearing Pressure
DaveAtkins
RE: Calculate Allowable Soil Bearing Pressure
RE: Calculate Allowable Soil Bearing Pressure
RE: Calculate Allowable Soil Bearing Pressure
f-d
¡papá gordo ain’t no madre flaca!
RE: Calculate Allowable Soil Bearing Pressure
Never, but never question engineer's judgement
RE: Calculate Allowable Soil Bearing Pressure
It seems like (a geotech engineer) may be able to put together a recommendation based on information using a borehole drilled adjacent to the slab- given a large caviot on what this recommendation is based on, that the geo engineer is not responsible for losses, ect. If nothing else maybe a square sawcut and hand auger by someone equally qualified. You can always fill in using grout or more concrete. I've got to agree with you, though. A 4" unreinforced slab is not reasurring, given it's the engineer that's asking the question.
RE: Calculate Allowable Soil Bearing Pressure
RE: Calculate Allowable Soil Bearing Pressure
If not, then with the slab broken out, you could do some hand samples with the split spoon and resulting SPTs (I did the back breaking job - using standard 140 lb hammer dropping 30 inches by hand - with driller's help on many occasions). You could drive, say 4 continuous spoons (if not hitting refusal first) which would give you the stratigraphy for about 8 ft depth (assuming you drive a 24 inch spoon for 4-6" blow counts. This seems to be a reasonable way to look at the problem.