"Bay Clay Loam" type of soil

[landerrain21]

Hi everyone,

I am working on a 4-storey residential/commercial building resting on a "Bay Clay Loam" type of soil (Located near the Bay from the word itself). As I am still awaiting for the tests(Shear wave velocity, SPT and undrained shear strength) to be done, I would like to ask your opinion if the soil is categorized as stiff soil or soft soil? In my observation, it has a fine granules which is friable when dry, but very sticky when wet.

Thanks for the help.

 

[BigH]

You need to have an assessment of the consistency (such as Undrained shear strength) to access as to whether the material is stiff or soft. Typical relationships for clays (TYPICAL, I say):
N = 0-2: very soft
N = 2-4; soft
N = 4-8: firm or medium (USA)
N = 8-15: stiff
N = 15-30: very stiff
N > 30 hard
How did you collect the sample without the SPT??

 

[landerrain21]

The "Bay Clay Loam" is from the area's geomorphology, based on previous tests and study. I am just using it for initial sizes only.

I am still waiting for the test results on this. Appreciate your input.

 

[fattdad]

Hopefully, you'll have something other than SPT to guide your strength evaluations. The pocket penetrometer is a good field tool when all you have is SPT samples. N-values (properly presented by BigH) have some relavence, but soil sensitivity can make them useless.

You need to spend money on proper drilling and undisturbed tube samples. You need to baby your tubes and let them ride vertically in the comfort of your car (i.e., not the back of some pickup truck or otherwise in the care of the drillers).

Unconsolidated undrained triaxial strength testing seems indicated (doctor talk, eh?).

This being the San Francisco Bay Mud, eh?

f-d

¡papá gordo ain’t no madre flaca!