【摘要】 将巴颜喀拉地块和四川地块作为研究对象,用块体边界上的GPS位移作为输入数据,应用边界元法计算得到块体边界上的应力,再用求解出的边界应力计算块体内部的位移与应变。结果发现巴颜喀拉块体南北向为张应变作用;块体西侧张应变量较大,向东逐渐减小,到龙门山东侧应变几乎减弱为零。南北向张应变向东的迅速减弱,使得龙门山断层产生闭锁,闭锁使龙门山断裂聚集起巨大的应变能,应变能的大量积累可能是导致汶川地震发生的根本原因。更多还原

【Abstract】 Takes Bayan Har and Sichuan crustal block as object of study,and takeing GPS displacement on boundary as input data and solves the variation of stress on block boundary,the variation of stress on block bounhdary is solved with Boundary Element Method and the distributions of displacement and strain in the two blocks are calculated and ploted from the stress.It is found out that NStrending tensile strain decreased quickly from west to east in Bayan Har crustal block before Wenchuan Ms8.0 earthquake,thus made the Longmen mountains fault locked,great strain energy accumulated and the earthquake occured.更多还原