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众所周知,断层阶跃在某些情况下可使破裂贯通,而在另外的一些情况下则可能使破裂终止。然而,不同摩擦定律公式对跨越破裂的影响尚未得到广泛的探讨。本研究采用二维动态有限元方法探讨张性和压性两种环境下不同摩擦参数如何影响破裂跨越阶跃的能力。我们比较了线性滑动弱化摩擦和三种速率—状态依从摩擦:衰变定律、滑动定律、强速率弱化滑动定律。我们发现,对于相同有效滑动弱化距离的摩擦参数,该摩擦定律的函数形式可对最大跨越距离有显著影响。将摩擦定律调整为具有等效破裂能量时,我们发现这种摩擦定律的函数形式对跨越破裂的影响次之。最后,我们发现采用特定参数时,一旦破裂在次断层段重新起始,跨越阶跃系统的破裂延迟可导致先前未曾见到的超剪切转换模式,即使初始应力场阻碍这种转换也如此。对复杂几何形态如断层阶跃采用多种摩擦定律进行研究可有助于更好地认识和理解破裂性质对模型及统计分析中采用的摩擦定律类型的依赖性。
It is well-known that fault steps can break through in some cases and terminate in other cases. However, the influence of different friction law formulas on the rupture of bursts has not yet been widely discussed. In this study, two-dimensional dynamic finite element method was used to investigate how different frictional parameters affect the ability of rupture to cross the step under both tensile and compressive conditions. We compare the linear sliding weakening friction and the three rate-state compliance friction: the decay law, the sliding law, the strong rate weakening sliding law. We find that for the friction parameters of the same effective sliding weakening distance, the functional form of the friction law can have a significant effect on the maximum spanning distance. When we adjust the law of friction to have equivalent energy of rupture, we find that the functional form of this law of friction is second to rupture. Finally, we find that with certain parameters, the rupture delay across the step system can lead to a trans-shear transition mode not seen before, even if the initial stress field blocks the transition, once the rupture restarts in the secant section. Research on complex geometries, such as fault steps, using multiple friction laws can help to better understand and understand the dependence of fracture properties on the model and the type of friction law used in statistical analysis.