Soil Mechanics and Foundation
A tri-axial shear test is preferred to direct shear test, because

Precise measurement of pore pressure and change in volume during test, is not possible
It can be performed under all three drainage conditions with complete control
Stress distribution on the failure plane, is non uniform
None of these

ANSWER DOWNLOAD EXAMIANS APP

Soil Mechanics and Foundation
The shear strength of a soil

Decreases with increase in normal stress
Is directly proportional to the angle of internal friction of the soil
Is inversely proportional to the angle of internal friction of the soil
Decreases with decrease in normal stress

ANSWER DOWNLOAD EXAMIANS APP