1962年3月19日新丰江6.1级水库诱发地震时的构造应力

对1962年3月19日新丰江MS6.1水库诱发地震震源附近的花岗岩质构造岩,进行三轴强度实验。根据实验结果,利用摩尔强度理论探讨该地震发震时的构造应力。研究表明:①1962年3月19日新丰江MS6.1水库诱发地震发生时,构造应力在震源处岩体断裂面上应力集中部位的剪应力已高达164MPa,为该处抗剪强度的97%;其它走向、倾向相似的无应力集中的断裂面上的剪应力(构造应力)约为18MPa。②在近代构造应力场中,新丰江岩体中只有走向在N30°±50°W范围内的断裂,才存在破裂的可能。

A study on the tectonic stress variation caused by Xinfengjiang Ms 6.1 reservoir induced earthquake occured on March 19, 1962

The granitoid tectonite samples collected near the epicenter of Xinfengjiang MS 6.1 earthquake occured on March 19,1962 were taken to make triaxial intension test in order to study the tectonic stress variation when the earthquake occurred.The result indicates that the shear stress on the stress concentration parts of the fracture plane in the epicenter was high to be 164Mpa,which was 96.5 percent of the shearing strength in the same place while the induced earthquake happened.The shear stress on other non-stress concentration parts was only about 18Mpa.It is impossible that the fractures in Xinfengjiang rock mass break except those with the strike in the range of N 300 500 W.