锦屏二级水电站引水隧洞大型原位试验研究Ⅱ——试验成果分析  

IN-SITU TEST ON DIVERSION TUNNEL AT JINPING II HYDROPOWER STATION Ⅱ—ANALYSIS OF RESULTS

作　　者：褚卫江 张春生[2] 陈平志[2] 程武伟[2] 张晨 刘宁[2] 

机构地区：[1] 浙江中科依泰斯卡岩石工程研发有限公司,浙江杭州310014 [2] 中国电建华东勘测设计研究院,浙江杭州310014 [3] 雅砻江流域水电开发有限公司,四川成都610051

出　　处：《岩石力学与工程学报》2014年第8期1702-1710,共9页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金青年基金项目(51109221)

摘　　要：在已有研究的基础上介绍原位试验的监测成果。本次原位试验显示引水隧洞掘进过程中，掌子面前方1.2倍洞径的围岩即会产生位移和应力变化，同时也会产生一些微破裂，掌子面后方0～10 m的范围是应力变化最剧烈的区段。声发射监测显示掌子面前方-5 m至掌子面后方10 m的范围是围岩损伤破裂密集产生的区段，掌子面后方超过10 m区段围岩的损伤破裂基本趋于稳定。光纤光栅监测成果显示靠近洞壁破围岩损伤比较严重的区域会出现滞后破裂现象，即掌子面效应完全消失后，一些浅表层的微裂纹会仍会形成宏观裂纹。引水隧洞开挖后右侧拱肩的围岩损伤最为严重，深度约3 m。多点位移计测试成果显示隧洞开挖过程中围岩的变形问题并不突出，深埋隧洞的监测工作应以松动圈测试、锚杆应力监测、围岩应力监测、光纤光栅监测和声发射监测为主，辅以适量的多点位移计监测。This paper presents the in-situ test results on the basis of the previous research. The in-situ tests showed that the deformation,the stress change and the microcrack initiation occurred in the the rock mass at didtance of 1.2 times of the diameter of diversion tunnel ahead of the excavation front,and the stress changed greatly in the rock mass 2-10 m behind tunnel front. The data of acoustic emission indicated that the rock mass in the range from 5 m ahead of the tunnel frount to 10 m behind the tunnel front produced the most acoustic emission energy during tunnelling and the acoustic emission was largely stable when the tunnel front was 10 m ahead of the acoustic emission monitoring section. The results of the optical fiber Bragg grating monitoring indicated that some closed cracks the rock mass close to the wall with serious excavation damage and subcritical crack growth reopened or further propagated even when the tunnel face effect disappeared. The most serious excavation damage occurred on the right spandrel and the damage zone was about 3 m in depth. The results from the multipoint displacement meter monitoring showed that the deformation of surrounding rock during tunnel excavation was not siginificant. The monitoring of deep tunnelling should therefore mainly focused on the measurement of excavation damage zone,stress in the rock bolts,stress in rocks,optical fiber Bragg grating and acoustic emission measurement and supplemented with a small number of multi-point displacement meters.

关 键 词：水利工程 原位试验 深埋隧洞 岩石应力 光纤光栅 声发射 

分 类 号：TV22[水利工程—水工结构工程]