Development of a New Nonlinear Unified Strength Theory for Geomaterials Based on the Characteristic Stress Concept

Abstract

AbstractThere is a need for a unified strength criterion, which is a variable suitable for describing the different strength properties of different types of geomaterials. There have been efforts to develop unified strength criteria; however, they are usually based on a mechanistic approach with adjustable failure planes and complex expressions. This study presents an alternative mechanistic approach to developing a simple unified strength theory by an adjustable characteristic stress. The characteristic stress is unique for a certain geomaterial. The frictional rule is used to explain the failure mechanism of geomaterials, and by defining the shear strength as a proportion function of normal stress acting on the failure plane, a new nonlinear unified strength theory is developed, which is similar to the Drucker-Prager strength theory. The strength curves of this theory are a series of continuous and smooth conical loci, which are located between Drucker-Prager and Matsuoka-Nakai strength curves in the de...