Definition - What does Shear Strength mean?
Shear strength can be defined as the ability of the soil to resist shearing forces. It gives a measure of the ability of the soil mass to resist internal resistance per unit area to failure and sliding along any plane within it.
It is an important parameter in designing sub-surface structures as it helps engineers to analyze soil stability factors such as bearing capacity and slope stability. When shear strength exceeds the limiting shear strength, failure will occur.
The triaxial consolidated undrained compression test is carried out to determine the shear strength of the soil.
Trenchlesspedia explains Shear Strength
Shear strength tests are carried out for analyses of short term and long term slope stability. The shear strength of the soil is controlled by factors such as its composition, initial state (consolidated, unconsolidated, stiff, soft), soil structure (disturbed, undisturbed, stratified, isotropic), loading conditions, etc.
The triaxial shear test determines the shear strength of soil i.e. cohesion and angle of internal friction and can be used to measure the total and effective stress of the soil.
In the triaxial consolidated undrained compression test for measuring shear strength, the pore pressure of the soil is measured and the soil is consolidated under pressure from all around in a triaxial cell before failure is induced by increasing the major principal stress.
The test is conducted as per the American Standard for Testing Material (ASTM) D4767-11. The measurement of shear characteristics is carried out under undrained conditions.