Analysis of the potential mechanisms of rockbursts

Abstract

Sudden slip on geological faults or other discontinuities in rock may be preceded by an initial phase of "slow" fault creep. A simple plane strain model of a suddenly loaded fault is analysed to illustrate the possible transition from stable slip behaviour to accelerated, unstable slip. The model assumes that a peaked shear load is applied suddenly to the fault region. The rate of slip movement is assumed to be proportional to the difference between the applied shear stress and the cohesive and frictional slip resistance. It is found that the evolutionary fault movement can be described succinctly by a non-linear ordinary differential equation describing the activated length of the sliding fault as a function of time. The differential equation is found to depend on a single, dimensionless parameter whose value determines whether the fault slip decays monotonically or accelerates in an unstable manner.