Numerical Simulation of Rock Creep Behavior with a Damage-Based Constitutive Law

Abstract

AbstractTime-dependent creep behavior of rocks is crucial not only for assessing geophysical hazards, such as earthquake rupture and volcanic eruption, but also for analyzing the long-term stability of rock engineering structures, such as underground mines and underground excavations. In the present paper, multiple stress-stepping creep tests on green sandstone under uniaxial stress conditions were performed. Results from stress-stepping creep experiments show that creep strain rates are highly dependent on the level of applied stress. Then, a time-dependent creep model based on damage constitutive law at a mesoscale was proposed to model the time-dependent behavior of heterogeneous brittle rocks. In the proposed model, the rock heterogeneity is considered by assuming the rock parameters following a statistical Weibull distribution, and both the maximum tensile strain criterion and the Mohr-Coulomb criterion are used as two damage thresholds to control the rock damage. The damage-based creep model is impl...