Abstract: We study:(1) A nonlinear model of thrust movement-a contact model, (2) The methods of explicit and implicit calculation of thrust stress field, (3) Thrust stress field characteristics from explicit and implicit scheme. We describe a thrust movement model and get stress field near the fault by 2D explicit finite difference method and 3D implicit finite element method, respectively. The results show that (1) the lower part of hanging wall of the thrust is tensile, and the lower part of foot wall is compressive, (2) complicated 3D tectonics can be treated as a series of 2D problems under some limitations, (3) explicit algorithm is better than implicit algorithm when a contact model is used to simulate stress field of active faults.

Key words: Reversed fault, Stress field, Finite difference method, Finite element, Contact model

摘要： 采用二维显式有限差分法与三维隐式有限单元法,分别计算了模型剖面上断层逆冲运动和三维断层逆冲运动伴随的断层邻域应力场。结果表明:(1)逆冲断层上盘下端部发育张应力场,下盘下端部发育压应力场;(2)对复杂的三维构造,在一定限定条件下,可以转化成二维问题进行计算;(3)显式差分法与隐式有限单元,都能较好地用接触模型模拟活动断层的应力场特征。

关键词: 逆断层, 应力场, 有限差分法, 有限元, 接触模型