Arresting mechanism of earthquake faulting

地震断层的几何复杂性将是地壳力学不均匀的表现。因此，它将与动态地震断裂的阻挡机制密切相关。详细研究了地震断裂作用的复杂性与断裂阻挡机制的关系。断裂带中存在的高压流体对地震破裂有促进作用。在本研究项目中，还研究了孔隙流体对地震破裂的影响，特别是对破裂的止裂作用。我们在边界积分方程法(BIEM)的基础上发展了模拟任意形状破裂的数值方法。这种Biem治疗的困难之一是超奇异积分的计算。我们首先从正则化方法出发，导出了一组非超奇异边界积分方程组，包括弹性动力方程和弹性静力学方程，用于分析任意S…更多的是成形的二维裂缝。对带侧枝的动态裂纹进行了数值模拟。模拟结果表明，侧枝的存在降低了主裂纹扩展尖端的应力集中。这说明裂纹的分支在地震破裂的减速和阻挡机制中起着重要的作用。基于正则化方法的方法有些复杂，因此我们接下来发展了一种更有效的方法来处理有限部分的超奇异积分。利用该方法可以方便地对任意形状的二维裂隙进行非稳态动态扩展的数值模拟。如果发生地震破裂，断层流体和破裂之间会发生非线性的机械相互作用。我们对相互作用的分析表明，如果断裂带中流体的分布高度不均匀，那么流体可以成为阻止地震破裂的因素。较少

Geometrical complexity of earthquake faults will be a manifestation of mechanical inhomogeneities of the earth's crust. It will therefore be closely associated with the arresting mechanism of dynamic earthquake faulting. A detailed study was carried out on the relation between the complexity of earthquake faulting and the arresting mechanism of faulting.High-pressure fluids existing in a fault zone can promote an earthquake rupture. The effect of pore-fluids on the earthquake rupture, especially on the arresting of rupture, is also studied in this research project.We developed new numerical methods to simulate an arbitrary-shaped rupture on the basis of boundary integral equation methods (BIEM). One of the difficulties in such a BIEM treatment is the evaluation of hypersingular integrals. We first made a formulation from the regularization approach, and derived a set of non-hypersingular boundary integral equations, both elastodynamic and elastostatic, for the analysis of arbitrarily s … More haped 2-D cracks. We carried out the simulation of dynamic cracks with side-branches. The results of the simulations show that the stress concentration at the propagating tip of the main crack is lowered by the presence of the side-branches. This suggests that the branching of the crack plays an important role in the deceleration and arresting mechanism of earthquake rupturing.The method based on the regularization approach is somewhat complicated, so that we next developed a more efficient method taking finite parts of hypersingular integrals. Numerical simulation of unsteady dynamic propagation of arbitrarily shaped 2-D cracks will be easily carried out using this method.It is well known from field observations that a fault zone is generally regarded as fluid conduit. If an earthquake rupture takes place, non-linear mechanical interactions occur between the fault fluids and the rupture. Our analysis of the interactions showed that the fluids can a factor to arrest the earthquake rupture if there is a high inhomogeneiry in the distribution of the fluid in the fault zone. Less