Assessment of the influence of discontinuity constitutive models for modelling fractured rock masses

Abstract

Understanding and properly simulating discontinuity mechanical behaviour is crucial in all rock engineering projects. Several constitutive relationships have been proposed and implemented in numerical codes. This paper discusses the results of a numerical study that exam-ines the influence of adopting different rock discontinuity constitutive models for simulating the behavior of a fractured rock mass. Two constitutive approaches are employed: an enhanced Cou-lomb-based criterion with strain softening and a modified version of the Barton-Bandis model to overcome potential implementation issues. These models have been implemented in PLAXIS and their performance is inspected through numerical analyses of an underground cavity for a specific discontinuity network geometry. The results provide insights into the implications and suitability of adopting different discontinuity constitutive models for assessing the stability of engineering works in fractured rock masses.