Laboratory methods of determining shear strength

Laboratory methods of determining shear strength

Following are some of the methods for determining shear strength of the soil.

1. Laboratory test.
2. Field test.

Laboratory test:

There are three types of laboratory test.

Direct shear test

It is one of the oldest laboratory tests performed to check the strength of the soil. To determine the shear strength of the cohesion soil direct shear device is used.

Unconfined compression test

This test is used only to determine the shear strength of the cohesion soils. The vane shears are suitable just for sensitive clays.

Triaxial compression test

It is a common method used to determine the mechanical properties of the deformable s0olids such as soil. The basic concept in method is that, the stress applied in vertical direction is some what different from the stresses applied in horizontal direction on the side of the cylinder.

There are three basic types of triaxial compression test of determining shear strength.

These are

1. The Un-consolidated un-drained (UU) test.
2. The consolidated un-drained (CU) test.
3. The consolidated drained (CD) test.