(1. Institute of Rock Instability and Seismicity Research,Dalian University of Technology,Dalian,Liaoning 116024,China;
2. School of Mining Engineering,University of Science and Technology Liaoning,Anshan,Liaoning 114051,China)
Abstract:The characteristics and laws of rockburst at diversion tunnels in Jinping II hydropower station are summarized through analyzing a mass of rockburst incidents recorded during tunneling,including the law of distribution of rockburst along tunnel axis,the way of failure of rock surrounding tunnels,the distribution of rockburst incidents in tunnel cross-section,the relationship of rockburst and distance from working face,the relationship of rockburst and time after construction,the relationship between types of rockburst and the length of failure,etc. According to these laws and the relationship of the rockburst and the geologic structure,the laws of the effect of geologic structure on the mechanism of rockburst are analyzed. Rockbursts at deep tunnels in hydropower station are monitored and predicted by using microseismic monitoring technique to real-time monitor and analyze the microseismic incidents. Based on the results of microseismic monitoring of rockburst,the relationship of the temporal and spatial change rules of microseismic activity and rockburst incidents is preliminary discussed. The results of study show that there exists laws of temporal,spatial and intensity distribution of rockburst;geologic structure,construction method,construction disturbance and many other factors all have a significant effect on the behaviors of rockburst;and the geologic structure has a control function. There always be a process of gestation before rockburst,with a lot of micro-fractures emerging and microseismic energy losing(microseismic indication). Microseismic activities always occur ahead of rockburst,while the locations of them coincide with rockburst,thus the safety of construction can be guaranteed. The actual test in this project shows that it is available and reliable to predict rockburst using microseismic monitoring technique,so as to provide a new idea for prediction of rockburst and safe construction.
张文东1,马天辉1,唐春安1,唐烈先2. 锦屏二级水电站引水隧洞岩爆特征及微震监测规律研究[J]. 岩石力学与工程学报, 2014, 33(2): 339-348.
ZHANG Wendong1,MA Tianhui1,TANG Chun′an1,TANG Liexian2. RESEARCH ON CHARACTERISTICS OF ROCKBURST AND RULES OF MICROSEISMIC MONITORING AT DIVERSION TUNNELS IN
JINPING II HYDROPOWER STATION. , 2014, 33(2): 339-348.
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