Arresting mechanism of earthquake faulting

地震断层的阻止机制

• 批准号: 08640522
• 负责人: YAMASHITA Teruo
• 金额: $ 0.9万
• 依托单位: University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08640522/
• 关键词: fault; boundary integral equation method; rupture; 亀裂; 相互作用

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

地震断层的几何复杂性是地壳力学不均匀性的表现。因此，它将与动力地震断层的制动机制密切相关。对地震断裂活动的复杂性与断裂活动的阻滞机制的关系进行了详细的研究，认为断裂带中存在的高压流体可以促进地震破裂。本文还研究了孔隙流体对地震破裂的影响，特别是对破裂停止的影响，在边界积分方程方法的基础上发展了新的数值方法来模拟任意形状的破裂。在这样的BIEM处理的困难之一是超奇异积分的评价。本文首先从正则化方法出发，导出了一组非超奇异的弹性动力学和弹性静力学边界积分方程，用于分析任意形状的弹性材料， ...更多信息 形成二维裂缝。我们进行了模拟动态裂纹与侧支。模拟结果表明，侧支的存在降低了主裂纹扩展尖端的应力集中。这表明裂纹的分支在地震破裂的减速和阻止机制中起着重要作用。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，采用超奇异积分的有限部分。用这种方法可以很容易地对任意形状的二维裂纹的非定常动态扩展进行数值模拟。如果发生地震破裂，断层流体和破裂之间会发生非线性的力学相互作用。分析表明，如果断裂带内流体分布具有很强的不稳定性，流体可以成为阻止地震破裂的因素。少

项目成果

山下輝夫: "Mechanical effect of fluid migration on the complexity of seismicity" Journal of Geophysical Research. 102. 17797-17806 (1997)

Teruo Yamashita：“流体运移对地震活动复杂性的机械效应”地球物理研究杂志 102。17797-17806 (1997)。

多田 卓: "Non-hypersingular boundary integral equations for two-dimensional non-planar crack analysis" Geophysical Journal International. 130. 269-282 (1997)

Takashi Tada：“二维非平面裂纹分析的非超奇异边界积分方程”《国际地球物理学杂志》130. 269-282 (1997)。

Tada T.: "Non-hypersingular boundary integral equations for two-dimensional non-planar crack analysis" Geophys.J.Int.130. 269-282 (1997)

Tada T.：“二维非平面裂纹分析的非超奇异边界积分方程”Geophys.J.Int.130。

山下 輝夫: "Mechanical effect of fluid migration on the complexity of seismicity" Journal of Geophysical Research. 102. 17797-17806 (1997)

Teruo Yamashita：“流体运移对地震活动复杂性的机械效应”地球物理研究杂志 102。17797-17806 (1997)。

多田卓・山下輝夫: "Non-hypersingular boundary integral equations for two-dimensional non-planar crack analysis" Geophysical Journal International. 130. 269-282 (1997)

Taku Tada 和 Teruo Yamashita：“二维非平面裂纹分析的非超奇异边界积分方程”《国际地球物理学杂志》130. 269-282 (1997)。