Modeling yield propagation of jointed synthetic rock

Abstract

To investigate the failure of non-continuous jointed rocks under compression loading, many researchers have performed uniaxial and biaxial compression tests. In this paper, I simulated numerically the behavior of artificial jointed rock under axial loading and compared it with laboratory experiments. The numerical model in this paper uses Mohr-Coulomb shear strength criterion with parameters of cohesion, friction, and tensile strength as tested in the laboratory. Artificial rock samples with 75° bridge angle were tested in the laboratory under uniaxial loading until failure. Curvilinear cracks (wing crack) initiated near the joint tips and propagated toward the other inner joint tip. The numerical model showed that tensile stress concentration caused wing crack initiation due to stress flow around the pre-existing non-persistent open joints. I compared the yielding behavior of the numerical simulation - under two tensile strength failure criteria - and the laboratory tests; the results showed significant agreement between the two tests. In this all compressive load environment, tensile stress concentration originated yielding at the inner joints' tips and formed continuous yielding surfaces in the bridge area.