Shear Stress

Definition

Shear stress is the component of the stress tensor , at any given point within a rock or soil mass, which is acting on plane of interest that passes through that point.

Overview

The stresses acting at any point and on any arbitrary plane within a rock or soil mass can be expressed in terms of the stress vector normal to the plane and the stress vector parallel to the plane (Fig. 1) (Jaeger et al. 2007). The stress component acting on the arbitrary plane is the shear stress for that particular plane of reference. This plane of reference can be an imaginary section of the soil or rock mass or represent a real boundary or discontinuity (joints, sliding surfaces).

Fig. 1

Illustration of stress components, in two dimensions (plane stress condition), parallel and normal to the planes is defined by the xy coordinate system and on a rotated plane defined by the x′y′ coordinate system; the positive z axis is pointed out of the page toward the viewer. Also shown are the stress tensors...