Problem $5(25\%)$:

A saindy soil has an internal friction angle ${}^{\text{'}}=35.$ In a consolidated$-$drained $($CD$)$ triaxial test, the sandy soil specimen failed at a deviator stress $({}^{\text{'}}{}^{\text{'}}-{}^{\text{'}}{)}_f=300k\frac{N}{m^2}.$

Part a $(10\%)$: Draw Mohr's circle at failure condition and include the Mohr$-$Coulomb failure criterion.

Part b $(5\%)$: What is the radius of Mohr's circle at failure?

Part c $(5\%)$: What is the chamber confining pressure, ${}^{\text{'}}3(k\frac{N}{m^2})?$

$(5\%)$: What is the major principal stress at failure, ${}_1^{\text{'}}(k\frac{N}{m^2})?$