【摘要】 为探讨汶川MS8.0地震对龙门山断裂带现今地应力环境的影响,2009年10—12月,在龙门山断裂带的北川、江油地区开展了3个200m深度钻孔水压致裂地应力测量,获得了汶川MS8.0地震发生1年多以后断裂带附近地壳浅表层地应力环境.根据研究区内的原地应力测量结果及汶川MS8.0地震引起的断层错动等资料,运用线弹性有限元数值模拟方法,计算得到了由断层错动位移所产生的附加应力,并推算了ZK02和ZK03位置震前应力分布特征.通过对比分析,揭示了断裂带附近地应力场的变化规律,探讨了汶川MS8.0地震对龙门山断裂带附近地应力环境的影响.更多还原

【Abstract】 In order to investigate the influence of Wenchuan MS8.0 earthquake on in-situ stress state near the Longmenshan fault zone, hydraulic fracturing measurements in three 200 m-deep boreholes were carried out in Beichuan and Jiangyou areas near the fault zone from Oct. to Dec. , 2009, and the distribution of current in-situ stress there at the time more than 1 year after the earthquake was analyzed. Based on the in-situ stress measurements and coseismic fault displacement in the study areas, the distribution of additional stress induced by fault motion was calculated with a linear-elastic finite element simulation, and then distribution of the principal stress at the two boreholes before the earthquake was calculated. Finally, the influence of Wenchuan MS8.0 earthquake on in-situ stress state in a superficial zone near Longmenshan fault was discussed through comparative analysis.更多还原