Abstract The distance between the fault and the underground cavern affects the surrounding rock mass stability, which is of great importance to the design and construction of the large-scale underground cavern especially the underground powerhouse. This study focuses on the distance effects of the fault on the rock mass stability of the main powerhouse at the Huanggou pumped-storage power station. Firstly, a microseismic monitoring system was constructed to investigate the distribution and mechanism of distance-dependent damage of the surrounding rock masses of the main powerhouse. Then, the rock failure process analysis and strength reduction method (RFPA-SRM) was adopted to reproduce the failure processes of the surrounding rock masses of the main powerhouse at different distance to the fault f34. Finally, by comparing the numerical simulation results with microseismic monitoring results, the distance effects of the fault f34 on the damage mechanism and failure modes were discussed. It can be concluded that when the distance is low, the damage of the surrounding rock masses subjected to excavation evolved from the spandrel toward the fault, eventually causing a V-shaped collapse if the strength reduction continues. As the distance increases, the effects of the fault on the damage mechanism and failure modes are reduced and the safety factor of the underground cavern is improved. The findings are expected to provide references for evaluating the surrounding rock mass stability of an underground powerhouse under complex geological conditions.

中文翻译：

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黄沟抽水蓄能电站主厂房断层距离对围岩稳定性的影响

摘要 断层与地下洞室的距离影响围岩体的稳定性，对大型地下洞室特别是地下厂房的设计和施工具有重要意义。本研究重点研究黄沟抽水蓄能电站主厂房断层距离对岩体稳定性的影响。首先，构建了微震监测系统，研究了主厂房围岩距离相关损伤的分布及机理。然后，采用岩石破坏过程分析与强度折减法（RFPA-SRM），再现了主厂房与断层f34不同距离围岩的破坏过程。最后，通过数值模拟结果与微震监测结果的对比，探讨了f34断层距离对损伤机理和失效模式的影响。可以得出结论，当距离较小时，开挖围岩的破坏由拱肩向断层方向发展，如果强度继续降低，最终会导致V型坍塌。随着距离的增加，断层对破坏机制和破坏模式的影响减小，地下洞室的安全系数提高。研究结果有望为复杂地质条件下地下厂房围岩稳定性评价提供参考。讨论了故障f34对损伤机制和失效模式的距离影响。可以得出结论，当距离较小时，开挖围岩的破坏由拱肩向断层方向发展，如果强度继续降低，最终会导致V型坍塌。随着距离的增加，断层对破坏机制和破坏模式的影响减小，地下洞室的安全系数提高。研究结果有望为复杂地质条件下地下厂房围岩稳定性评价提供参考。讨论了故障f34对损伤机制和失效模式的距离影响。可以得出结论，当距离较小时，开挖围岩的破坏由拱肩向断层方向发展，如果强度继续降低，最终会导致V型坍塌。随着距离的增加，断层对破坏机制和破坏模式的影响减小，地下洞室的安全系数提高。研究结果有望为复杂地质条件下地下厂房围岩稳定性评价提供参考。如果强度继续降低，最终会导致 V 形坍塌。随着距离的增加，断层对破坏机制和破坏模式的影响减小，地下洞室的安全系数提高。研究结果有望为复杂地质条件下地下厂房围岩稳定性评价提供参考。如果强度继续降低，最终会导致 V 形坍塌。随着距离的增加，断层对破坏机制和破坏模式的影响减小，地下洞室的安全系数提高。研究结果有望为复杂地质条件下地下厂房围岩稳定性评价提供参考。