Soil Mechanics And Foundation MCQ Questions & Answers | Civil Engineering

The correct answer is (A) decreases.

Here's why:

A consolidated drained (CD) test means we're testing a soil that is:

* Consolidated: The soil has been compressed and excess pore water pressure has dissipated.
* Drained: Water is allowed to escape freely during the shearing process.

A normally consolidated clay is a clay that has never experienced a stress greater than its current stress.

When a normally consolidated clay is sheared under drained conditions, the soil particles tend to rearrange themselves into a denser configuration.

This rearrangement and compression of the soil structure causes the overall volume of the soil sample to decrease. Because water is allowed to drain, this volume change can occur.

Therefore, the answer is decreases.

In soil mechanics, the shear strength of a soil is a unique function of

both effective stress and total stress.

The shear strength of soil depends on both the effective stress and the total stress acting on the soil mass.

Effective stress refers to the stress carried by the soil grains themselves, while total stress includes the stress carried by both the soil grains and the pore water.

Therefore, the correct option is both effective stress and total stress.