Introduction

Many geotechnical systems comprise a soil or rock with an anisotropic strength definition. Consider, for example, a silty soil containing clay stratifications. The shear strength of the silt and clay could be very different. Similarly, the shear strength of jointed or fractured rock can vary significantly from one joint set to the next.

The compound strength model can be used to simulate anisotropic strength (i.e. directionally dependent) in soil or rock by considering the angular proximity of the column base plane to each joint set and the influence of the joint set on the shear strength. Details concerning the definition of Compound Strength can be found in the Slope Stability Modeling reference book. This example demonstrates how to define a compound strength material model for a problem involving two joints and a symmetric geometry.