Soil Mechanics and Foundation Engineering - Engineering

Q1:

A direct shear test possesses the following disadvantage:

A A relatively thin thickness of sample permits quick drainage

B A relatively thin thickness of sample permits quick dissipation of pore pressure developed during the test

C As the test progresses the area under shear, gradually changes

D none of these.

ANS:C - As the test progresses the area under shear, gradually changes

"As the test progresses, the area under shear gradually changes." In a direct shear test, the shear plane is subjected to shearing forces, and as the test progresses, the area of the shear plane changes due to the deformation of the sample. This can complicate the interpretation of the test results and may introduce errors in the analysis of shear strength properties of the soil. Therefore, the correct option is: "As the test progresses, the area under shear gradually changes."