Hi, I've been trying to find out how to determine the undrained shear strength of soil without having the unconfined compressive strength. I have 6 geotech reports, of which none tell me the unconfined compressive strength for the depth I need to bury my piping model. I do have the plasticity limits, STP test blows, and type of soil. I'm trying to get a more accurate model but cannot find anything that shows a correlation or alternative way to determine the undrained shear strength. Does anyone have any idea how to do this or an efficient way to get at least semi accurate data?

The undrained shear strength is obtained by a triaxial test, the name of test is "consolidated undrained Cu (or R) test".

There are correlations of Cu versus the "effective overburden pressure"- see for example Braja M. Das , Principles of Foundation Engineering, Seventh Edition.