摘要
为了研究锦屏二级水电站探涧开挖过程中发生岩爆与地应力的相关性，在电站探洞不同水平埋深处进行了水压致裂和应力解除三维应力测量。测量结果表明：（1）在探洞浅部，受局部地形影响，测点的应力分布主要受自重和区域及地形地貌控制。形成特有的“V”型河谷岸坡内的局部应力状态，最大主应力11．0MPa左右，作用方向NNW基本近水平；（2）在探洞深部地应力值较高，最大主应力40．0MPa左右，作用方向近直立；（3）随水平埋深的增大最大主应力由近水平状态转变为近直立状态，说明在洞深部自重应力起主导作用。对原地应力实测结果进行解析，得到了隧道横截面的最大主压应力和最小主压应力及相关的应力参量，结合岩爆判据对隧道发生岩爆的可能性进行了分析，提出了岩爆的发生主要受控于隧道横截面内的最大差应力的大小。
To study the relation between stresses and rock burst during tunnel excavation at Jinping Ⅱ hydro-power station, 3D in-situ stress measurements are carded out by hydraulic fracturing and over-coring from 130 m to 3 005 m along tunnel. The measured results are as following： （1） in-situ stress at shallow depth of tunnel is controlled by dead weight topography and region formation, and a typical stress distribution of ＂V＂ shape for river valley is formed. The maximum stress is about 11.0 MPa with the direction NNW. The in-situ stress at deep depth of tunnel is high with the maximum stress about 40 MPa, and the direction is about closely vertical： （2） the direction of maximum stress changes from level state to vertical state along with increasing of level burying, indicating that dead weight stress is the dominant effect, and （3） the maximum compression stress and minimum compression stress within the tunnel cross-section are obtained by stress analysis. The possibility of rock burst is analyzed with rock burst criterion. The rock bursts are controlled by different stresses within the tunnel cross-section and restrained by ground water growth.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2005年第A01期4822-4826,共5页
Chinese Journal of Rock Mechanics and Engineering
关键词
岩石力学
水压致裂
应力解除
地应力
岩爆
判据
rock mechanics
hydraulic fracturing
over-coring
stress
rock burst
criterion
