Check the correctness of the hybrid Lagrangian-discrete element method with rate and state dependent friction law and study on influence of fault dip angle on fault stick-slip
Fault stick-slip is a kind of frictional instabilities,which can induce many geohazards,such as earthquakes and mine earthquakes.At present,the research on fault stick-slip(including fault meta-instability)is mainly focused on experiments and numerical simulation based on continuum or discontinuum methods.To overcome shortcomings of continuum and discontinuum methods,some continuum-discontinuum methods combining advantages of both have been developed.To check the correctness of the hybrid Lagrangian-discrete element method,in which the rate and state dependent friction law was introduced,and to explore the influence of fault dip angle on fault stick-slip,firstly,the slip-hold-slip experiment of the sliding block-floor model was simulated.Then,the influence of fault dip angle of the biaxial compressive specimens was studied,and evolution of friction coefficient at the meta-instability stage of the fault stick-slip process was mainly focused.The following results were found.As the dip angle of the fault is increased,the regular zigzag shape of the relation between the absolute value of the averaged differential stress at the upper surface of the rock specimen and timestep becomes irregular;the number of timesteps for the first stick-slip,the averaged stress drop,the averaged stick-slip period and the averaged peak stress decrease.Before stick-slip stage,the friction coefficient and shear stress at each part of the fault surface are less different.When the fault enters the meta-instability stage,the averaged value of friction coefficient on the fault surface decreases faster,which can be regarded as one of the characteristics of the fault entering the meta-instability stage.After the rate and state dependent friction law is introduced,the fault stick-slip results of the hybrid Lagrangian-discrete element method is in a good agreement with the existing results(such as experimental results),but more abundant,reflecting the superiority of numerical simulation to a certain extent.
FaultFault stick-slipFault dip angleRate and state dependent friction lawMeta-instabilityNumerical simulation
万方数据
维普
