ABSTRACT
The stress–strain–strength relationship of soil can be changed from elastic to plastic behavior, or it can be changed from softening to hardening behavior if certain local environmental conditions change. In terms of stress–strain relationships, soil may be broadly categorized according to whether it is loose or dense or whether it is normally consolidated or overconsolidated. The stress–strain relationship for any material is used for analyzing its stability as part of an engineered system. Numerous failure criteria have been proposed for the stability analysis of soil mass, but most of them are borrowed from basic engineering mechanics. Failure criteria are classified as one-parameter model and two-parameter model. Shear strength is the maximum resistance a soil has to shearing stresses. In general, the elasticity- and plasticity-based models are commonly used for analysis of soils and rocks. There are three types of loading and drainage conditions under which shear tests may be performed, namely unconsolidated undrained, and consolidated undrained and consolidated drained.
