震源动力学破裂过程数值模拟研究

Review on numerical simulation of dynamic rupture process of earthquake source

首先阐述了震源动力学过程研究的重要意义,在此基础上,研究了复杂的断层几何形态及介质模型对动力学破裂过程的影响,并对常用的有限元方法、离散元方法、有限差分方法和边界积分方程方法等进行了相应介绍.讨论了这些数值模拟方法各自的优缺点,建议在方法的选择上应视具体问题及计算的精度而定.最后对动力学数值模拟的关键部分,滑动摩擦准则进行了论述.常用的滑动摩擦准则有滑动弱化准则、速率弱化准则和速率-状态依赖摩擦准则.在单纯考虑某个地震的动力学破裂传播过程时,滑动弱化准则较为常用,其中滑动弱化距离的选取至关重要.但若考虑整个地震循环,速率-状态依赖摩擦准则更为合适.

This paper emphasized the importance of studying dynamic rupture process of earthquake source. In this study, we investigated the influences of complex fault geometry and medium, and introduced some numerical methods, such as finite element method, discrete element method, finite difference method and boundary integral equation method. We further discussed advantages and disadvantages of these methods and suggested that the choice of the methods depend on the concrete problem and calculation accuracy. Finally, we discussed the application of slip friction law to the dynamic simulation. Commonly used friction laws were slip-weakening law, slip rate-weakening law and rate-state dependent friction law. If we simply considered the dynamic rupture process of a single earthquake, slip-weakening law was more widely used, in which choosing reasonable slip weakening distance was very important. However, if we studied a whole seismic cycle, rate and state dependent friction law would be more appropriate.