UPSC Civil Service Exam Questions - Engineering

Q1:

A clay soil specimen when tested in unconfined condition gave an unconfined compressive strength of 100 kN/m2. A specimen of the same clay with the same initial condition is subjected to a UU triaxial test under a cell pressure of 100 kN/m2. The axial stress (in kN/m2) at failure would be

A 150

B 200

C 250

D 300

ANS:B - 200

The correct answer is B.

An unconfined compressive strength qu = 100 KN/m2.

for uu test σ1/σ3=σ1/'σ3=qu

σ1=σ1= 100 + 100 = 200 KN/m2.