猴子岩水电站地下厂房开挖过程微震特征与稳定性评价  

Microseismicity and stability evaluation of the underground powerhouse at Houziyan hydropower station subjected to excavation

作　　者：徐奴文[1,2] 戴峰[2] 李彪[2] 朱永国 程丽娟[4] 王琦[1] 

机构地区：[1]山东大学土建与水利学院,山东济南250100 [2]四川大学水力学与山区河流开发保护国家重点实验室,四川成都610065 [3]国电大渡河猴子岩水电建设有限公司,四川康定626005 [4]中国电建集团成都勘测设计研究院有限公司,四川成都610072

出　　处：《岩石力学与工程学报》2016年第A01期3175-3186,共12页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家重点基础研究发展计划(973)项目(2015CB057903);教育部新世纪优秀人才(NCET–13–0382);国家自然科学基金面上项目(51374149)~~

摘　　要：为了实时监测和评价开挖过程猴子岩水电站地下洞室群围岩稳定性以及识别洞室潜在风险区域,综合应用数值模拟、微震监测、常规监测和现场调查等多种手段方法,得到如下结论:(1)微震监测可以实现开挖强卸荷过程地下洞室群围岩稳定性的实时监测、分析和评估;(2)微震活动性的时空演化规律可以识别和圈定地下洞室群岩石微破裂集中区及潜在风险区域;(3)微震监测可以很好地揭示开挖诱发的岩石微破裂萌生、发育、扩展直至贯通全过程。结合地下洞室群现场施工和加固工况,微震事件的空间集聚可以看作是降低该区域施工进度的前兆信息;(4)常规监测方法(多点位移计、收敛计和锚杆应力计等)可以很好地验证微震活动的真实性和有效性。研究结果表明微震监测、数值模拟、常规监测和现场调查综合方法对于深入认识复杂地质条件和开挖强卸荷过程中地下洞室群开挖行为和施工安全控制具有重要意义。同时,研究成果也可为地下洞室群后期开挖和加固提供参考。In order to real time monitor and evaluate the surrounding rock mass stability and identify the potential hazardous regions of the underground caverns at the Houziyan hydropower station subject to excavation, the comprehensive method incorporating numerical simulation, microseismic（MS） monitoring, traditional monitoring and field observation was adopted. Some results are obtained as follows： （1） MS monitoring can realize the real-time monitoring, analysis and evaluation of surrounding rock mass stability of the underground caverns due to excavation-induced unloading. （2） micro-fractures concentration areas of surrounding rock mass and potential hazardous regions in the underground caverns were delineated by the temo-spatial evolution of microseismicity. （3） on, propagation and coalescence of micro-fractures due to excavation can be reflected by MS monitoring. With regard to the field construction and reinforcement of the underground caverns, the obvious and intense concentrations of MS events have already been regarded as the early warning of reducing the construction schedule. （4） the conventional monitoring methods such as multi-point extensometers, convergence gauges and anchor stress gauges, etc., were used to verify the truthfulness and effectiveness of the results of MS monitoring. The presented results demonstrate that the combination of MS monitoring, numerical modeling, traditional surveying and in situ observation approaches lead to a better understanding of excavation behavior of underground caverns and a more satisfactory control of the working in terms of safety in the complex geological and excavation-induced unloading conditions. Furthermore, the results can provide some guidelines for later excavations and supports of the underground powerhouse.

关 键 词：水利工程 微震监测 数值分析 稳定性 地下洞室 猴子岩水电站 

分 类 号：TV642[水利工程—水利水电工程]