Question

A clay soil specimen when tested in unconfined condition gave an unconfined compressive strength of $100kN/m^2$. A specimen of the same clay with the same initial condition is subjected to a $UU$ triaxial test under a cell pressure of $100kN/m^2$. Axial stress $($in $kN/m^2)$ at failure would be

• A. $150$
• B. $200$
• C. $250$
• D. $300$

Answer 1

The correct option is B $200$

Unconfined compressive strength
$q_u=100kN/m^2$
For UU test,
${\sigma }_1-{\sigma }_3=q_u$
$\therefore {\sigma }_1=100+100=200kN/m^2$