断层影响带地应力特征及稳定性验证

摘要

To analyze the characteristics of the in-situ stress field of the two fault influence zones in a tunnel in the Fujian province,the hydraulic fracturing method was adopted in two boreholes near the fault influence zones in the tunnel middle section to measure the in-situ stress.The results show that the stress in the test area accords with the general rule of stress distribution,with horizontal principal stress increasing with depth,and local fractures resulting in higher or lower stress values regarding some test points.The maximum horizontal principal stresses in the two testing holes are in the same direction of NNW.The results are consistent with the regional tectonic stress field and are also close to results concerning the intact rock zone in the same region.Based on the test results,the characteristics of the in-situ stress of the test area were analyzed and the stability of the fault where the two testing holes lie was validated by adopting the lower limit of the sliding criterion.%为研究分析福建某隧道两断层影响带的地应力场特征,在其隧道中部断层影响带附近两钻孔中采用水压致裂法进行了地应力测试.测试结果表明:断层影响带测试区地应力符合一般地应力分布规律,水平主应力随深度增加有增大趋势,局部裂隙导致部分测点应力值偏高或偏低；两测孔最大水平主应力方向一致,均为NNW向.该测试结果与区域构造应力场基本吻合,也接近于同区域围岩完整区地应力测试成果.文章根据该测试成果分析了该测试区的地应力特征,并采用滑动准则下限验证了两测孔所在的断层的稳定性.