锦屏深埋大理岩破裂扩展时间效应与控制效果评价  

TIME-DEPENDENT BEHAVIOR OF CRACK PROPAGATION AND EVALUATION OF CONTROL EFFECT OF JINPING DEEP MARBLE

作　　者：张春生[1] 刘宁[1] 朱焕春 褚卫江 吴家耀 

机构地区：[1]中国水电顾问集团华东勘测设计研究院,浙江杭州310014 [2]浙江中科依泰斯卡岩石工程研发有限公司,浙江杭州310014

出　　处：《岩石力学与工程学报》2013年第10期1964-1972,共9页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(51109221)

摘　　要：锦屏二级水电站大理岩在高的地应力条件作用下表现出破裂随时间扩展的现象,给引水隧洞的运行期安全产生重大的影响。现场开挖后出现的滞后破裂现象、锚杆应力计和声波测试都反映出大理岩破裂随时间发展的特征。首先采用室内试验和数值分析,证明破裂是大理岩开挖后的主要响应方式,表明锚杆应力计和声波测试在现场测试中具有更好的适用性,而多点位移计敏感性较差。利用GSI随时间指数递减代表大理岩强度随时间递减,进而表征隧洞开挖损伤区随时间的增加而增加,在此基础上,建立应力腐蚀模型SC。将现场已获得的监测数据作为SC模型中相关参数的校核依据,对大理岩的长期力学响应、锚杆受力状态和衬砌结构安全性进行详细分析,采用SC模型得出的特征与现场实际开挖响应具有很好的一致性。The marble of Jinping II hydropower station diversion tunnel shows a phenomenon of crack propagation with time under high geostress,which impacts significantly the run-time safety of diversion tunnel. The lag fracture after excavation,monitoring results by bolt stress meter and sound wave test all reflect the characteristic of crack propagation with time. The laboratory test and numerical analysis are adopted to prove that the fracture is the main response way of marble after excavation,which indicates that a bolt stress meter and sound wave test have better applicability,and multipoint displacement meter sensitivity is worse. The behavior of GSI decreasing exponentially with time is used to stand for marble strength decreasing with time,and further behalf on tunnel excavation damage zone increasing with time. Based on the theory,the stress corrosion（SC） model is set up. The obtained field monitoring and testing data are used to check the related parameters of SC model. The long-term mechanical response of marble,anchor stress state and lining structure security are analyzed in detail;and these characteristics consist well with the actual excavation response.

关 键 词：岩石力学 大理岩 破裂扩展 应力腐蚀 高地应力 开挖响应 

分 类 号：TU45[建筑科学—岩土工程]