断层三维转动及其引起的地表形变空间分布特征
Relationship Between Faults Three-Dimensional Rotation and Surface Deformation
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摘要: 以向错理论为基础,在断层一维转动与地表形变关系研究的基础上,推导了弹性半空间均匀介质中断层三维转动与地表形变的关系,对不同深度和倾角的断层以不同方式转动产生的地表形变的曲线变化特征进行了分析,计算了断层以不同方式转动产生的地表水平位移和垂直形变的空间分布特征,结果表明:1)断层转动对地表位移的影响随着断层深度的增加不断衰减,地表位移对不同倾角的断层转动有不同的响应,其中以断层角点为转动轴的断层向错引起的地表形变受倾角的影响最为显著;2)断层以不同方式转动相同的量产生的水平位移和垂直形变在数值上大小相近,垂直形变的空间分布与断层的转动方式有关;3)断层三维转动与滑动引起的地表形变在数值大小上有区别,但具有相同的量级,空间上断层滑动引起的形变范围相对转动较为广泛。最后,讨论了断层向错理论在地壳形变分析中存在的问题。Abstract: The formulas to express surface deformation caused by three-dimensional fault rotation in a half space of an elastic homogeneous medium was derived based on the relationship between 1D rotation and surface deformation of a fault with a changed depth and dip. The varying surface displacement due to imparity rotation was analyzed and the horizontal displacement and vertical deformation calculated for a fault that rotates in several ways. The results show:1)Surface displacement diminishes with the increment of fault depth responding differently to the fault dip angle. The most significant fault surface deformation was when the rotation axes was the fault corner; 2)The model value is nearly equal in numerical when the fault rotates the same angle in different ways, the spatiak distribution of vertical deformation was closely related to the rotation ways;3)The surface deformation caused by 3D rotation has some distinctive numerical sliding characteristics but at the same magnitude. Regarding the spatial range, deformation due to fault sliding is more extensive than rotation. Finally, problems in disclination theory and crustal deformation research are discussed.