Constitutive Model for Rocks

Abstract

A constitutive model based on the theory of plasticity is proposed and used to characterize stress‐deformation behavior of rocks. It allows for factors such as hardening, volume changes, stress paths, cohesive and tensile strengths, and variation of yield behavior with mean pressure. It is applied to characterize behavior of three hard rocks: Sandstone, Westerly Granite, and Dunham Dolomite. The constants for the model are determined from series of available laboratory tests conducted under different initial confinements and stress paths obtained by using multiaxial and cylindrical triaxial testing devices. The model is verified with respect to observed laboratory responses. Overall, the proposed model is found suitable to characterize the behavior of the rocks and involves less or equal number of constants compared to available models of similar capabilities and is easier to implement in (numerical) solution procedures.