论文标题
关于2D地震破裂模拟中3D应力状态的重要性
On the importance of 3D stress state in 2D earthquake rupture simulations with off-fault deformation
论文作者
论文摘要
在过去的几十年中，已经开发了许多数值模型来研究地震和无性震动的条件。这些模型探讨了嵌入在弹性或非弹性介质中的摩擦断层的行为，并提交到远场负载（地震循环模型）或初始应力（单个动态破裂模型）中。这些初始条件都会影响故障和OFFEART动态。由于断层应力直接测量的稀疏性，建模者必须对这些初始条件做出假设。直到今天，安德森的理论是唯一可用于将断层产生和重新激活与三维应力场联系起来的框架。在这项工作中，我们研究了三维应力场在对平面晶体条件下建模2D滑滑断层中的作用。我们表明，基于安德森的理论设置不正确的初始应力场可能会导致对所研究情况的损伤区宽度低于六倍。此外，由于断层滑移与off损变形之间的相互作用，初始应力场会影响破裂的传播。我们的研究强调，即使在2D数值模拟中，也需要建立正确的初始3D应力场。
During the last decades, many numerical models have been developed to investigate the conditions for seismic and aseismic slip. Those models explore the behavior of frictional faults, embedded in either elastic or inelastic media, and submitted to a far field loading (seismic cycle models), or initial stresses (single dynamic rupture models). Those initial conditions impact both on-fault and off-fault dynamics. Because of the sparsity of direct measurements of fault stresses, modelers have to make assumptions about these initial conditions. To this day, Anderson's theory is the only framework that can be used to link fault generation and reactivation to the three-dimensional stress field. In this work we look at the role of the three dimensional stress field in modelling a 2D strike-slip fault under plane-strain conditions. We show that setting up an incorrect initial stress field, based on Anderson's theory, can lead to underestimation of the damage zone width by up to a factor of six, for the studied cases. Moreover, because of the interactions between fault slip and off-fault deformation, initial stress field influences the rupture propagation. Our study emphasizes the need to set up the correct initial 3D stress field, even in 2D numerical simulations.
