Undrained Shear Strength vs. Cohesion

[transmissioneng]

If a Soils Testing Laboratory gives you Unconfined Compressive Strength (qu) Values for Rock Core strength tests, can you assume that the Cohesion of the Rock is equal to half of those values- i.e. qu/2?

Thanks!

 

[dgillette]

Refer to post on Foundation Engineering. (Please don't cross-post.)