论文部分内容阅读
贵广高铁广西段位于广西盆地东北部,是连接“一带一路”的高速通道,为查明研究区的地应力分布特征,为隧道的设计提供基础资料,在广西5个不同地区开展了8个钻孔的水压致裂地应力测量工作,结果表明:研究区内最大水平主应力S_H方向主要表现为NNW-NWW,这与华南区域应力场相一致;S_H和最小水平主应力S_h的梯度小于全国平均地应力梯度。在深度小于300 m的范围内,三向主应力相对大小以S_H>S_h>S_v为主,在这种应力状态下有利于逆断层的活动;在深度大于300 m的范围内,三向主应力相对大小以S_H>S_v>S_h为主,在这种应力状态下有利于走滑断层的活动,这种应力状态与研究区以逆断兼走滑的断层结果较为一致。研究区侧压力系数的值和μ_m值(最大剪应力与平均主应之比)均表明测区内断层处于稳定状态,这与研究区属于构造稳定区的研究结果相一致。
The Guangxi section of Gui-Guang-Gao-Tie Railway is located in the northeast of Guangxi Basin and is a high-speed access road connecting the “Belt and Road”. In order to find out the characteristics of stress distribution in the study area and provide basic information for the design of the tunnel, five sections in Guangxi The results show that: the direction of the maximum horizontal principal stress S_H in the study area is mainly NNW-NWW, which is consistent with the stress field in South China; the gradient of S_H and the minimum horizontal principal stress S_h Less than the national average stress gradient. In the depth of less than 300 m, the relative magnitude of the three-direction principal stress is dominated by S_H> S_h> S_v, which is favorable for the reverse fault activity in this state of stress. For the depth greater than 300 m, The relative size is mainly S_H> S_v> S_h, which is conducive to the strike-slip fault activity in this state of stress. This stress state is consistent with the faulted and run-off faults in the study area. The value of the lateral pressure coefficient and the value of μ_m (the ratio of the maximum shear stress to the average principal stress) of the study area indicate that the faults in the survey area are in a stable state, which is consistent with the research results that the study area belongs to the structural stability area.