白鹤滩水电站左岸边坡开挖卸荷过程微震视应力特征研究  

Analysis of microseismic apparent stress characteristics of the left bank slope at Baihetan hydropower station subjected to excavation

作　　者：张敏[1,2,4] 徐奴文[1,2] 陈文夫[3] 谭尧升[3] 戴峰[1] 蒋雄 李韬[1] ZHANG Min;XU Nuwen;CHEN Wenfu;TAN Yaosheng;DAI Feng;JIANG Xiong;LI Tao(State Key Laboratory of Hydraulics and Mountain River Engineering,Sichuan University,Chengdu,Sichuan 610065,China;Stake Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu University of Technology,Chengdu, Sichuan 610059,China;China Three Gorges Corporation,Beijing 100038,China)

机构地区：[1]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 [2]成都理工大学地质灾害防治与地质环境保护国家重点实验室,四川成都610059 [3]中国长江三峡集团公司,北京100038 [4]中国矿业大学

出　　处：《岩石力学与工程学报》2018年第A02期4133-4141,共9页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(51679158);国家重点基础研究发展计划(973)项目(2015CB057903);成都理工大学地质灾害防治与地质环境保护国家重点实验室开放基金(SKLGP2016K018)~~

摘　　要：微震事件视应力可反映岩质边坡应力变化情况。以白鹤滩水电站左岸边坡为研究背景,分析岩质边坡爆破开挖卸荷过程微震视应力与能量、地震矩的关系,重点研究微震视应力在爆破开挖前后变化特征,结合数值模拟,通过微震视应力变化情况开展边坡稳定性评价。研究结果表明:微震视应力随地震矩和辐射能量的增大而增大;高视应力微震事件的出现可反映工程施工中的强烈爆破开挖扰动程度;通过微震视应力分布特征圈定的主要损伤区与RFPA3D数值模拟结果基本吻合;视应力急剧下降,累积视体积呈增长趋势,是边坡围岩变形的前兆信号。研究成果可为基于微震监测的类似大型岩石边坡稳定性评价提供参考。Blasting excavation of the rock slope produces geometry changes which will induce stress redistribution within the rock mass. The stress redistribution can be reflected by the apparent stress of micoseismic(MS) events. The apparent stress of MS events increases along with the seismic moment and radiated energy. High apparent stress in rock mass can reflect the disturbance degree subjected to intense blasting excavation. The distribution characteristics of high MS apparent stress in the left bank slope can delineate the main damage regions,which is in good agreement with the result of numerical simulation using the Realistic Failure Process Analysis code in three-dimension(RFPA3 D). The period that the average daily apparent stress reduces strongly and the cumulative apparent volume increases can be regarded as the precursor of the deformation of rock slope. The present achievements can provide some references for the stability evaluation of similar high rock slopes based on microseismic monitoring.

关 键 词：岩石力学 边坡稳定 视应力 微震监测 视体积 白鹤滩水电站 

分 类 号：TU45[建筑科学—岩土工程]