【摘要】 在四川省大凉山腹地深度分别为190.15 m和364.10 m的两个钻孔中进行水压致裂地应力测量,以获得当前浅部地壳应力的状态.测量结果表明,在测试段深度内,实测最大水平主应力最高值为14.68MPa,与该区域内已有近似深度地应力测量结果(20 MPa)相比,此次测值有所降低;3个主应力之间的关系为:最大水平主应力>最小水平主应力>垂直应力,表明大凉山地区地壳浅部构造应力场以水平应力为主导;最大水平主应力方向为北西至北西西向,与区域活动构造的性质和震源机制解得出的主压应力方向基本符合;最后,利用库伦摩擦滑动准则,讨论了当断层摩擦因数μ为0.6~1.0时,测区内主要断裂在该应力状态下的稳定性,认为测区内现今最大水平主应力值暂时没有达到使区域逆断层发生瞬间摩擦滑动的临界值.更多还原

【Abstract】 By the hydro-fracturing method,in-situ stresses were measured in two drill holes at 190.15 m and 364.10 m to obtain the in-situ stress state of the shallow crust.The results indicate that the maximum value of the maximum horizontal principal stress is 14.68.MPa at the depths,which is lower than the previous measurement(20.MPa);The relation among the three principal stresses is the maximum horizontal principal stress﹥the minimum horizontal principal stress﹥the vertical stress,which reveals that the horizontal stress is larger than vertical static-rock pressure in the hinterland of Daliang Mountain;The direction of maximum principal tectonic stress is NW-NWW,which is in accordance with the implications from regional active faults and the direction of the principal compressive stress obtained by the focal mechanism solutions.Finally,Coulomb Friction criteria was used to investigate the stability of the active structure in the hinterland of Daliang Mountain,and μ(u is the friction coefficient) was 0.6～1.0.The results show that the maximum horizontal principal stress has not reached the critical value of momentarily sliping of reverse fault activity.更多还原