Which shear test of soil is typically performed in a laboratory?

The triaxial shear test is a laboratory procedure used to determine the shear strength of soil under controlled conditions. In this test, soil samples are placed in a cylindrical chamber and subjected to confining pressure, which simulates the pressures found in the ground. The test can differentiate between different drainage conditions—drained, undrained, and consolidated—allowing for a more comprehensive understanding of the strength characteristics of soil under varying stress conditions.

This test is particularly valuable because it provides information on the effectiveness of soil under different loading conditions and helps engineers make informed decisions regarding soil stability and potential failure in construction projects. Additionally, the ability to control the confining pressure and sample drainage makes it a versatile and widely applicable test in geotechnical engineering.

While other tests like the direct shear test, shear vane test, and unconfined compressive strength test have their own applications and contexts, the triaxial shear test stands out for its ability to replicate field conditions more accurately and provide detailed insights into soil behavior under stress.