断层端部裂纹扩展相似模拟试验及力学机理

基于相似理论制作符合实际地层力学性质的先存断层模型试件，分析在一定地应力条件下试件破坏过程；利用断层端部应力场理论，揭示先存断层构造产生相应破坏模式的机理。结果表明，随着载荷的增加，微裂纹逐渐发育扩展，扩展路径逐渐趋向于加载方向，在裂纹扩展的过程中会伴随产生多条分支路径，随后裂纹相互汇合贯通使试件破坏，利用断层端部应力场理论可以判定新产生的破裂方向，其与先存断层产生的主要破坏的角度具有一致性。 

Similar model test and mechanical analysis of fault structure

The pre-existing fault specimens were made to confirm the actual stratum mechanical properties based on the similarity theory. Then the mechanism of failure mode of pre-existing fault was analyzed under the crack tip stress field theory. The results show that with the increase of load, the microcracks develop gradually and propagate, and the propagation path tends to the loading direction. In the process of crack propagation, multiple branch paths are generated, and then the cracks merge with each other to destroy the specimen. The stress field theory can be used to determine the newly generated fracture direction, which is consistent with the main failure angle of the pre-existing fault.