UPSC Civil Service Exam Questions - Engineering

Q1:

A soil fails under an axial vertical stress of 100 kN/m2 in unconfined compression test. The failure plane makes an angle of 50° with the horizontal. The shear parameters c and φ respectively will be

A 41.9 kN/m2, 0

B 50.0 kN/m2, 0

C 41.9 kN/m2, 10°

D 50.0 kN/m2, 10°

ANS:C - 41.9 kN/m2, 10°

(&sigma)1 = (sigma)3 * tan^2(50) + 2Ctan50.

(&sigma)3=0 for the unconfined compression test.

(σ)1=2Ctan50.
C=100/2tan50,
C=41.9.

The failure plane angle = 45+x/2.
50=45+x/2
X=10