HELP - CBR, Atterberg limits, angle of friction correlation
HELP - CBR, Atterberg limits, angle of friction correlation
(OP)
G'day!
I have a geotechnical report on a very big area of land which contains the averaged CBR and Angle of internal friction plus the individual testing report for CPT, SPT, and even a trial fill testing.
I want to check the validity of the average and derive some specific values for an area.
Query:
1.) Can anyone point out the correlation of an angle of internal friction to CBR value or vice versa?
2.) Any other correlations from Atterberg limits, CPT, SPT reports to Soil modulus, CBR, and Cohesion? have derived Su, angle of internal friction from these but have no correlation to others. need the CBR and Es for industrial slab design.
( Im a structural engineer and would like to know more on the geotechnical aspects so i can review a geotechnical report and not just use the values recommended...)
Cheers!
I have a geotechnical report on a very big area of land which contains the averaged CBR and Angle of internal friction plus the individual testing report for CPT, SPT, and even a trial fill testing.
I want to check the validity of the average and derive some specific values for an area.
Query:
1.) Can anyone point out the correlation of an angle of internal friction to CBR value or vice versa?
2.) Any other correlations from Atterberg limits, CPT, SPT reports to Soil modulus, CBR, and Cohesion? have derived Su, angle of internal friction from these but have no correlation to others. need the CBR and Es for industrial slab design.
( Im a structural engineer and would like to know more on the geotechnical aspects so i can review a geotechnical report and not just use the values recommended...)
Cheers!





RE: HELP - CBR, Atterberg limits, angle of friction correlation
f-d
¡papá gordo ain’t no madre flaca!
RE: HELP - CBR, Atterberg limits, angle of friction correlation
http://www.slideruleera.net/contributions.html
RE: HELP - CBR, Atterberg limits, angle of friction correlation
thanks for these leads and advise.
For the correlations, i just want to check the results and recommended values for validity. double checking instead of just blindly accepting the values.
and to know more about geotech which i find intriguingly challenging...
for other leads or tips. do give me more info.
ta!
Cheers!
RE: HELP - CBR, Atterberg limits, angle of friction correlation
in other words, as frustrating as it may be, trust your geotech. geotechnical engineering is very complicated even though it seems like it's "just dirt" to some people. if you don't trust them, you can always hire a second geotech but don't be surprised to find different results (there's always different ways to evaluate things on top of the range of test results that you'll usually see when different folks test the same material). here's a better idea, if you bought a cheap geotech, try going with a more reputable firm even if it costs more on the front end. quite often (but not always), the cheap guy will give you the more conversative (and maybe inappropriate) recommendations. either way, if you don't trust the geotech, get a new one. if you don't trust them because you don't have a clue as to what they are recommending, then i'd suggest you find a firm you trust and stick with them...firing firms over something you don't understand may not be in your best interest. if you trust them, then discuss the test results/recommendations with the firm. ask questions about how the results they provided compare to what they typically see (sometimes, there's oddball results that pop up). to learn more about the testing we do and to see some generalized results/ranges, check out the navfac/ufc library:
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UFC 3-220-10N Soil Mechanics
by the way, hire "the firm" (or quality), not the results that you expect them to give you as results can be widely varying from sample to sample or site to site. i often see clients (perhaps customers is more appropriate a word) end up hiring firms other than my firm simply because they were either 5% cheaper or because they will give out "cheap" rcommendations or the recommendations that they were looking for. in the end, those customers usually end up coming back to us because the other guys weren't quite worth saving a few bucks on the front end of the project. some of those customers are now clients...some are not (can't win them all i suppose).
good luck (both on the project and understanding geotechs...we're very complicated creatures).
RE: HELP - CBR, Atterberg limits, angle of friction correlation