A triaxial sample of loose sand is tested in lateral extension (LE) (see Fig. 13.7). The...

A triaxial sample of loose sand is tested in lateral extension (LE) (see Fig. 13.7). The sample is first consolidated nonhydrostatically, with The sample is then failed in LE, and the angle of internal friction is 30° (c = 0).

(a) Draw the Mohr circles for both initial and "at failure" conditions.

(b) What will be the major and minor principal stresses at failure?

Reference: Fig. 13.7