Does soil with c'=12kPa and φ'=32° fail under given principal stresses?

[EzaMoo]

Homework Statement

A*certain*soil*has*c’*=*12kPa*and*φ’*=*32°.*The*major*and*minor*principal*stresses*at*a*point*in*this*
soil*are*348*and*160*kPa*respectively,*and*the*pore*water*pressure*at*this*point*is*96*kPa.*Draw*
the*failure*envelope*and*the*Mohr*circle*and*determine*if*a*shear*failure*will*occur*at*this*point*in*
the*soil.*If*so,*determine*the*angle*between*the*failure*plane*and*the*plane*on*which*the*major*
principal*stress*acts.*

Homework Equations

As attached.

The Attempt at a Solution

As attached. But how do I know if failure has occurred?

 

[EzaMoo]

*Bump*