UU, CU, and CD test. Need some explanation here.

[sadiqrosli90]

Can someone explain the differences in drainage conditions between UU, CIU and CID tests and what the relevancy of the shear strength parameters obtained from the different tests in the design of geotechnical structures.

I'm still searching about this topic but I couldn't get the answer.

 

[fattdad]

the first two are undrained tests (i.e., the change in pore pressure will influence test results) and the last one is drained (i.e., run so slow that excess pore pressures don't develop. For the middle one, most often there is a pore pressure transducer to measure changes in pore pressure.

The extent to which you get positive or negative pore pressures during shear depends on the critical void ratio and the density of the sample when tested.

f-d

¡papá gordo ain’t no madre flaca!

 

[beyfadn]

The undrained tests UU CU are used to evaluate the capacity of the soil in short-term. The Drained test gives us an idea the soil in long term.
the short-term is often what to take into considération.

 

[massagung]

i have same question,
pls help, its triaxial test UU, CU, and CD are can applied of any kind of soil type, or not? if can, whether the TX CD value (cohession parameter) is always less than UU or CU??

M.A.

 

[GeoPaveTraffic]

These are fairly basic soil mechanics questions, so please be careful in how you are using information gained here.

In theory, and of the triaxial tests you list can be ran on any type of soil. However from a practical view point, most triaxial tests are ran on primarily cohesive soils (silts and clays).

The type of test should be selected to match the type of analysis being conducted.

Lastly, yes the cohesion intersept of a CD test will generally be less than the intersept of a UU test.

Mike Lambert

 

[massagung]

Thanks for your input Geo,

M.A.

 

[fattdad]

The CU test with pore-pressure measurements will return both effective (i.e., long-term) and total (i.e., short-term) strength parameters.

f-d

¡papá gordo ain’t no madre flaca!