Reasonable interpretation and monitoring optimization on excavation response of deep buried tunnel in hard rock
LIU Ning1,2,ZHANG Chunsheng1,SHAN Zhigang1,CHU Weijiang1,2
(1. PowerChina Huadong Engineering Corporation,Hangzhou,Zhejiang 310014,China;
2. HydroChina Itasca Research and Development Center,Hangzhou,Zhejiang 310014,China)
Abstract:In order to understand the state of surrounding rock timely and support type,it is necessary to depend on effective monitoring methods and reliable monitoring data in the process of underground engineering construction. Jinping II deep buried tunnel is given priority to brittle marble. The maximum depth is 2 525 m,more than 75% of the buried depth is more than 1 500 m. A large tunnel of 14 m diameter is excavated in such a complex geological environment,will face with the huge project risk. The target and indicative of monitoring method is difference from the shallow condition. The compression test and excavation response showed the main response after excavation of complete marble is not deformation,but fracture. A thorough interpretation was carried on deformation,stress and sound wave test result of Jinping II deep buried tunnel. Research results show that when the surrounding rock is failure,the deformation may still in the range of surrounding rock deformation control standards. The deformation monitoring has lost the significance of early warning,and the anchor stress meter is more sensitive on the state of the surrounding rock than multi–point displacement meter,and has more warning value. The acoustic test results were well consistency with anchor stress monitoring results. Finally,the numerical method was used to describe the internal stress state of surrounding rock in detail,and the brittle–ductile–plastic conversion characteristic of marble can reasonably explain the contradictory relationship between the deformation and fracture.
刘 宁1,2,张春生1,单治钢1,褚卫江1,2. 深埋硬岩隧洞开挖响应合理解译与监测优化[J]. 岩石力学与工程学报, 2020, 39(S1): 2818-2827.
LIU Ning1,2,ZHANG Chunsheng1,SHAN Zhigang1,CHU Weijiang1,2. Reasonable interpretation and monitoring optimization on excavation response of deep buried tunnel in hard rock. , 2020, 39(S1): 2818-2827.
冯夏庭,张传庆,李邵军,等. 深埋硬岩隧洞动态设计方法[M]. 北京:科学出版社,2013:1–20.(FENG Xiating,ZHANG Chuanqing,LI Shaojun,et al. Dynamic design method for deep tunnels in hard rock[M]. Beijing:Science Press,2013:1–20.(in Chinese))
[3]
徐干成,郑颖人,乔春生,等. 地下工程支护结构与设计[M]. 北京:中国水利水电出版社,2013:12–23.(XU Gancheng,ZHENG Yingren,QIAO Chunsheng,et al. Design of underground engineering support structure[M]. Beijing:China Water and Power Press,2013:12–23.(in Chinese))
[4]
MARTIN C D. Seventeenth Canadian geotechnical colloquium:The effect of cohesion loss and stress path on brittle rock strength[J]. Canadian Geotechnical Journal,1997,34(4):698–725.
[6]
EBERHARDT E,SREAD D,STIMPSON B. Quantifying progressive pre-peak brittle fracture damage in rock during uniaxial compression[J]. International Journal of Rock Mechanics and Mining Sciences,1999,36(3):361–380.
[5]
MARTIN C D,CHANDLER N A. The progressive fracture of Lac du Bonnet granite[J]. International Journal of Rock Mechanics and Mining Sciences,1994,31:643–659.
[8]
刘 宁,张春生,褚卫江,等. 深埋大理岩脆性破裂细观特征分析[J]. 岩石力学与工程学报,2012,31(增.2):3 557–3 565.(LIU Ning,ZHANG Chunsheng,CHU Weijiang,et al. Microscopic characteristics analysis of brittle failure of deep buried marble[J]. Chinese Journal of Rock Mechanics and Engineering,2012,31 (Supp.2):3 557–3 565.(in Chinese))
[10]
朱焕春,吴家耀,朱永生,等. 锦屏二级水电站引水隧洞围岩稳定、动态支护设计专题研究—2010年阶段性总结报告[R]. 武汉:Itasca(武汉)咨询有限公司,2010.( ZHU Huanchun,WU Jiayao,ZHU Yongsheng,et al. Research on surrounding rock stability,dynamic supporting design of Jinping II hydropower station diversion tunnel – 2010 stage summary report[R]. Wuhan:Itasca consulting Co.,Ltd.. 2010.(in Chinese))
[14]
张春生,陈祥荣,侯 靖,等. 锦屏二级水电站深埋大理岩力学特性研究[J]. 岩石力学与工程学报,2010,29(10):1 999–2 009.(ZHANG Chunsheng,CHEN Xiangrong,HOU Jing,et al. Study of mechanical behavior of deep-buried marble at jinping ii hydropower station[J]. Chinese Journal of Rock Mechanics and Engineering,2010,29(10):1 999–2 009.(in Chinese))
[9]
MARTIN C D,KAISER P K,MCCREATH D R. Hoek-Brown parameters for predicting the depth of brittle failure around tunnels[J]. Canadian Geotechnical Journal,1999,36(1):136–151.
[11]
READ R S. 20 Years of excavation response studies at AECL's underground research laboratory[J]. International Journal of Rock Mechanics and Mining Sciences,2004,41(8):1 251–1 275.
[12]
MARTINO J B,CHANDLER N A. Excavation–induced damage studies at the Underground Research Laboratory[J]. International Journal of Rock Mechanics and Mining Sciences,2004,41(8):1 413–1 426.
[13]
刘 宁,张春生,褚卫江. 锦屏深埋大理岩破裂特征与损伤演化规律[J]. 岩石力学与工程学报,2012,31(8):1 606–1 613.(LIU Ning,ZHANG Chunsheng,CHU Weijiang. Microscopic characteristics analysis of brittle failure of deep buried marble[J]. Chinese Journal of Rock Mechanics and Engineering,2012,31(8):1 606–1 613.(in Chinese))
[1]
何满潮. 深部的概念体系及工程评价指标[J]. 岩石力学与工程学报,2005,24(16):2 854–2 858.(HE Mao-chao. Conception system and evaluation indexes for deep engineering[J]. Chinese Journal of Rock Mechanics and Engineering,2005,24(16):2 854–2 858.(in Chinese))
[7]
MARTIN C D. The strength of massive Lac du Bonnet granite around underground opening[Ph. D. Thesis][D]. Winnipeg:University of Winnipeg,1993.