Numerical Simulation Of Co-Seismic Surface Deformation Of Strike-Slip Faults

Strike slip fault is one of the most common faults in nature,and it is prone to strong earthquakes.Therefore,taking the Tancheng earthquake in 1668 as the prototype and referring to its parameters,a three-dimensional finite element model of strike slip fault is established to simulate the fault movement during the earthquake.The fault sliding process and influencing factors of the strike slip fault are simulated by contact analysis,so as to enrich the relevant theory of fault displacement during earthquake occurrence.Through the analysis,we get the following preliminary understanding(1)Change the fault friction coefficient.The fault surface deformation width is compared when the friction coefficient is 0.6 and 0.8.When the friction coefficient is set as 0.6,the fault surface deformation width is greater than that when the friction coefficient is 0.8.(2)Change the boundary conditions of the model.The results show that the coseismic surface deformation of strike slip fault increases slowly with the increase of load.Through the calculation of the friction coefficient and boundary conditions of the basic model,the preliminary conclusions are as follows: the displacement of the stratum near the fault plane is the largest,and the displacement is smaller when it is farther away from the fault plane;the displacement rate of each node near the fault plane and its vicinity is about 5.58mm/a,which is 5.17mm/a according to the previous investigation results,which is generally consistent with the calculation results of this study;the surface fracture width of the fault surface is relatively large With the increase of load,the fracture width increases step by step,reaching a certain equilibrium state,the width remains unchanged,and the fracture width continues to increase with the increase of load.The smaller the friction coefficient is,the greater the surface deformation of strike slip fault is,and vice versa.