基于三维向错理论模拟倾角为60°的矩形断层在转动角不同量级和形式下引起的地表形变,分析断层转动对地表形变大小及空间分布的影响。利用向-位错模型,采用数值方法模拟鲜水河断裂带断层滑动与转动引起的地表形变,并与扣除趋势项的2009~2015年的GPS实测结果进行对比。研究表明:1)转动角大小与断层向错引起的地表位移场大小呈正比关系,位移场方向不变,转动方向不同时,地表位移场方向随之改变,大小不变,且断层附近地表位移场影响较大;2)基于向-位错组合模型对鲜水河断裂带模拟结果与GPS结果在大小和方向上均具有较好的一致性;3)鲜水河断裂带表现出一定的旋转特性,存在明显的分段差异性,具有一定的转换构造样式。
First, based on the three-disclination model, this paper simulates the surface deformation of the single fault, which has a dip angle of 60% under the different angle and direction of rotation,in or- der to analyze the influence of fault rotation on the size of the surface deformation field and the charac- teristics of spatial distribution. Second, based on the disclination-dislocation model, the surface de- formation caused by fault sliding and rotation of the Xianshuihe fault zone is simulated by numerical methods and is compared with the GPS data of 2009-2015, which eliminates the overall displacement. Result show: 1) the angle of rotation is proportional to the surface deformation caused by the disclina- tion of fault, but the displacement field direction remains the same; when the direction of rotation changes, so does the surface displacement field, but the size remains the same, with greater impact on the displacement field near the fault; 2) based on the disclination-dislocation model, the simulated re- sults and GPS measurements of the Xianshuihe fault zone show good consistency; 3) there are some characteristics of rotation in Xianshuihe fault zone, with obvious differences with every block, and a certain transformation tectonic style.