Analysis of faulting in three-dimensional strain field
Analysis of faulting in three-dimensional strain field
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DOI：
10.1016/0040-1951(78)90154-3
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发表时间：
1978-05
期刊：
影响因子：
2.9
通讯作者：
Z. Reches
中科院分区：
文献类型：
--
作者：
Z. Reches
从粘土实验到裂谷，在很宽的尺度上都观察到了由三组、四组或更多组断层组成的多断层。多断层通常可以用多期变形来解释。然而，在某些情况下，多个断层同时发育，因此，它们不能用一般的断层理论来解释。这些理论都是针对平面应变而导出的，而多断层则是针对三维应变而导出的，本文对三维应变场中的断层运动作了初步分析。该分析考虑了由于沿沿着断层组滑动而导致的理想化模型的变形;该模型受到应变边界条件的约束。分析表明：（1）三组或四组断层是容纳三维应变所必需的;（2）四组断层的组合使变形耗散最小;这些断层的方向取决于应变状态，以及（3）如果沿着这四组断层的滑动阻力是内聚的，则引起滑移的应力沿着它们等于或大于具有相同内聚力的Tresca刚塑性体的屈服应力。但这表明，当一个物体受到三维应变时，可能会形成多重断层和菱形断层模式。
Multiple faults, composed of three, four or more sets of faults, have been observed at a wide range of scales, from clay experiments to rift valleys. Multiple faults usually are explained by multiple phases of deformation. However, in several cases the multiple faults developsimultaneously; therefore, they cannot be explained by the common theories of faulting. Furthermore, these theories were derived for plane strain, whereas, multiple faults are associated with three-dimensional strain.An elementary analysis of faulting in three-dimensional strain field is presented here. The analysis considers the deformation of an idealized model due to slip along sets of faults; the model is subjected to strain boundary conditions. The analysis shows that (1) three or four sets of faults are necessary to accommodate three-dimensional strain, (2) there is a combination of four fault sets which minimize the dissipation of the deformation; the orientation of these faults depend on the strain state, and (3) if the resistance to slip along these four sets of faults is cohesive, then the stresses which cause slippage along them are equal or larger than the yielding stresses of a Tresca rigid-plastic with the same cohesion.The analysis presented here is too elementary to be directly applied to field observations; however, it indicates that multiple faults and rhomboid patterns of faults probably form when a body is strained three-dimensionally.