Joint Elasticity Effect on the Failure Behaviours of Rock Masses using a Discrete Element Model

It is widely accepted that the mechanical properties and failure behaviours of a rock mass are largely dependent upon the geometrical and mechanical properties of discontinuities. The effect of joint elasticity on the failure behaviours of rock masses is investigated using a discrete element model, namely, the synthetic rock mass model. Here, uniaxial compression tests of the numerical model are carried out for the rock mass model with a persistent joint to analyse the role of joint elasticity in the failure process with various joint orientations, β. A strong correlation between the joint elasticity and failure strength is found from the simulation results: a positive relationship when the joint orientation β < φj; a negative relationship when the joint orientation φj < β < 90 ◦ ; and a very limited effect when the joint orientation β = 90 ◦ . Additionally, it is shown that the joint elasticity is the governing factor in the transition of failure modes, especially from the sliding failure mode along the joint to the mixed sliding-tensile failure mode.