为了研究贯穿节理对隧道围岩稳定性的影响,基于强度折减法建立有限元数值模型,模拟计算了不同节理面倾角、贯穿位置、黏聚力和内摩擦角条件下隧道围岩稳定性安全系数,定量分析了隧道围岩稳定性与敏感因素之间的变化关系。结果表明:(1)贯穿隧道中心的节理面倾角对裸洞围岩稳定性影响较小,与之相比,贯穿拱脚的节理面的影响更明显,且隧道围岩稳定性安全系数随着贯穿节理倾角的增大而逐渐减小;(2)随着贯穿节理从隧道底部移动至顶部,围岩稳定性安全系数呈现先增后降的变化趋势,贯穿隧道中心时安全系数最大,贯穿位置越靠近隧道开挖边界则安全系数越小,贯穿隧道下半部分比贯穿上半部分对围岩稳定性影响更大;(3)随着节理面黏聚力、内摩擦角的增大,隧道围岩稳定性安全系数逐渐增大,且对内摩擦角的变化更敏感;(4)总结了贯穿隧道节理面的主要防治措施。研究成果可为节理较发育的隧道工程设计与施工提供参考。

In order to study the influence of penetrating joints on the stability of tunnel surrounding rock, a finite element numerical model was established based on the strength reduction method, and the stability safety factors of tunnel surrounding rock were simulated and calculated under different conditions of joint dip angles, through-going positions, cohesion and internal friction angles. The quantitative relationship between the stability safety factors of tunnel surrounding rock and the sensitive influencing factors was analyzed. The results show that: (1) The dip angle of joints passing through the tunnel center has a relatively small impact on the stability of the surrounding rock in the bare tunnel, and joints passing through the arch foot have a more significant influence. As the dip angle of the penetrating joints increases, the stability safety factor of the tunnel surrounding rock gradually decreases. (2) As the penetrating joints move from the bottom to the top of the tunnel, the stability safety factor of the surrounding rock first increases and then decreases. The stability safety factor is the highest when the joints pass through the tunnel center, and it decreases as the through-going position approaches the excavation boundary of the tunnel. There is a greater impact on the surrounding rock stability when joints pass through the lower half of the tunnel than those passing through the upper half. (3) As the cohesion and internal friction angle of the joint surface increase, the stability safety factor of the tunnel surrounding rock gradually increases, and greater sensitivity to changes in the internal friction angle. (4) The main prevention and control measures for joints passing through the tunnel were summarized. The research findings can provide references for the design and construction of tunnels in areas with well-developed joints.