Effect Of Different Factors On The Stick-slip Fault With A Numerical Simulation

We adopt the motion model such as spring-block model, and establish partial differential equations based on Dieterich&Linker rate-and-state dependent friction law, then use the numerical simulation method to study the impact of various factors on the shear stress and the stick-slip of the fault which include the rock stiffness surrounding the fault, the loading velocity of the tectonic forces and the change of the normal stress. Furthermore, we study the normal stress static (normal stress steps) and dynamic (stress pulses and wave packet) perturbations on the time to stick-slip.We show that the rock stiffness surrounding the fault can affect the stability of the fault, if the stiffness is less than the critical value, the fault appears stick-slip, and the number of the stick-slip increases with the stifness. If it is equal or greater than the critical value, the fault slip is stable. When the amplitude of variation of the tectonic forces loading velocity (which uses the loading rate of the spring to simulate) becomes larger, there is a increase in the amplitude of the stress drop and a decrease in the cycle of the stick-slip. When the normal stress changes, the fault shows the typical stick-slip characteristics, that is, the stress drop curves of stick-slip reveal zigzagged, and the characteristics become more apparent with the increased amplitude of variable normal stress. For the case of the normal stress static perturbations, there are two moments in the stick-slip cycle when the perturbations have the biggest impact on the time to the next stick-slip, if the perturbations load at the end of the cycle, they almost make no influence. The changes of the time to the stick-slip increase with the amplitude of the normal perturbations. For the case of the normal stress dynamic perturbations, it is a type of increased trend of the time variation of the stick-slip with the half duration of the pulse, there exists a critical period of the wave packet, the bigger amplitude or the latter loading time of the perturbations induce to bigger impact of the period of the wave packet on the change of the happening time to the stick-slip.