Characteristics of In-Situ Stress and Stability Validation
of a Fault Influence Zone
（1 Faculty of Engineering, China University of Geosciences, Wuhan 430074;
2 Key Laboratory of Geotechnical Mechanics and Engineering of the Ministry of Water Resources,
Yangtze River Scientific Research Institute, Wuhan 430010）
Abstract：
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.
2013, Vol. 50 