高应力地下厂房顶拱开挖过程围岩力学响应与稳定性分析  

Mechanical response and stability analysis of surrounding rock mass during roof arch excavation of underground powerhouse under high in-situ stress

作　　者：董林鹭 李鹏 李永红 赵铁拴 孙悦鹏 肖培伟[1,2] 杨兴国 徐奴文[1,2] DONG Linlu;LI Peng;LI Yonghong;ZHAO Tieshuan;SUN Yuepeng;XIAO Peiwei;YANG Xingguo;XU Nuwen(College of Water Resource and Hydropower,Sichuan University,Chengdu,Sichuan 610065,China;State Key Laboratory of Hydraulics and Mountain River Engineering,Sichuan University,Chengdu,Sichuan 610065,China;Guodian Dadu River Basin Hydropower Development Co.,Ltd.,Chengdu,Sichuan 610041,China;PowerChina Chengdu Engineering Corporation Limited,Chengdu,Sichuan 610072,China;China Gezhouba Group No.1 Engineering Co.,Ltd.,Yichang,Hubei 443002,China)

机构地区：[1]四川大学水利水电学院,四川成都610065 [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]国电大渡河流域水电开发有限公司,四川成都610041 [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 [5]中国葛洲坝集团第一工程有限公司,湖北宜昌443002

出　　处：《岩石力学与工程学报》2023年第5期1096-1109,共14页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(42177143,51809221);四川省杰出青年科学基金(2020JDJQ0011)。

摘　　要：水电站地下厂房洞室群地质结构复杂、地应力高,施工期间围岩变形破坏现象频繁发生。针对某水电站高应力地下厂房开挖卸荷诱发顶拱破坏的问题,开展围岩损伤演化过程分析。利用微震监测技术实时记录地下厂房开挖期间围岩微破裂萌生、发育及扩展过程。结合常规监测、现场踏勘,揭示深部围岩损伤与施工动态的响应规律。采用数值模拟重现开挖过程应力场与位移场的渐进演化特征。研究结果表明:微震活动与施工状态、地质条件密切相关,厂房K0–40~K0–60区域微震事件聚集由强卸荷及节理、裂隙共同控制。开挖卸荷形成的高边墙水平应力及顶拱垂直应力加剧了围岩损伤沿开挖轴向扩展演化。震源参数在围岩变形破坏前表现为矩震级增大、视应力下降、累计视体积不变。研究成果可为类似地下工程开挖围岩损伤及稳定性评价提供借鉴。The geological structure of underground powerhouse caverns of hydropower stations is complex and the ground stress is high.Deformation and failure of surrounding rock mass occur frequently during construction.In order to solve the failure of roof arch during excavation of high stress underground powerhouse of one power station,the damage evolution process of surrounding rock was analyzed.The microseismic(MS)monitoring technology was used to record the process of surrounding rock mass microfracture initiation and propagation during excavation of underground powerhouse in real time.The response laws of deep surrounding rock damage and construction dynamics were revealed through routine monitoring and site survey.The progressive evolution characteristics of stress field and displacement field during excavation were reproduced by numerical simulation.The research results show that the MS activity is closely related to the construction state and geological conditions.The MS events gathering in the K0-40-K0-60 area of the powerhouse are jointly controlled by strong unloading and joint fissures.The horizontal stress of the high side wall and the vertical stress of the top arch aggravate the damage evolution along the excavation axis.The focal parameters show that the moment magnitude increases,the apparent stress decreases,and the cumulative apparent volume remains unchanged before the deformation and failure of the surrounding rock mass.The research results can provide reference for the damage and stability evaluation of surrounding rock mass during excavation of similar underground engineering.

关 键 词：岩石力学 地下厂房 高应力 微震监测 数值模拟 稳定性分析 

分 类 号：TU45[建筑科学—岩土工程]