基于正交各向异性理论表征断层的变形行为

Characterization of Fault Deformation Behavior Based on Orthotropic Theory

总结了"介质弱化带"和"摩擦接触"这2类常见断层模型在地壳动力学数值模拟研究中的应用研究进展,再利用2者各自的特点,引入复合材料力学中各向异性理论,结合断层产状给出了针对不同走向、倾角的断层各向异性本构方程。数值模拟试验对比研究显示:基于正交各向异性本构关系的断层模型不但能够避免断层垂直方向上的形变场畸变现象,而且能够有效地刻画断层两盘相对滑动,模拟结果与基于接触摩擦断层模型的模拟结果吻合良好。该模型可以在研究区域构造复杂,接触计算收敛困难的情况下替代摩擦接触模型。

Two types of fault model,weak zone model and frictional contact model,and their applications in crustal dynamics simulation are summarized in this paper. Combined with their respective properties,the orthotropic theory is presented here to characterize the fault behavior. Take into account the fault strike and dip,the orthotropic constitutive equation in finite element simulation is presented in this paper. Numerical simulation result shows that the orthotropic fault model-based results agree well with the result-based on frictional contact model,both of them can characterize the relative sliding and shear behavior of the fault,without any distortional deformation in the vertical direction of the fault. This reasonable result indicates that,under the condition of the complex geological model and strict convergence of frictional contact based simulation,the orthotropic fault model can be employed to replace the frictional contact fault model to characterize the fault deformation behavior effectively.