摘要
通过对锦屏二级水电站引水隧洞施工期间大量岩爆记录的深入研究,分析总结出岩爆沿里程分布规律、岩爆围岩破坏方式、隧洞横断面岩爆位置规律、岩爆次数与距掌子面的距离关系、岩爆次数与开挖后暴露时间关系、岩爆烈度与其围岩破坏范围关系等岩爆特征规律。通过对这些规律及岩爆分布与地质构造之间关系的研究,总结地质构造和岩爆的相互作用规律。将微震监测技术用于引水隧洞工程施工,进行深埋隧洞的岩爆监测预警,实现对微震活动的全天候连续监测分析,并根据现场对岩爆的微震监测结果,对微震的时空演化与岩爆之间的关系进行初步探讨。研究结果表明:深埋岩体隧洞中,岩爆的时间、空间、强度等分布存在较明显的规律性,并且与地质结构、施工工法、施工扰动等影响因素之间有着必然的联系,其中地质结构对岩爆的发生起控制作用;岩爆发生之前普遍存在一个孕育过程,并伴随着大量微破裂的产生和微震能量的释放(微震前兆),微震活动对岩爆事件普遍具有时间优先性和空间一致性,可利用其指导安全施工。本文的工程实践验证了微震监测技术用于深埋岩体隧洞岩爆监测预警的可行性,并具有较高准确率,从而为隧洞的岩爆预测和安全施工提供新的研究思路。
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＆amp;nbsp;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.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2014年第2期339-348,共10页
Chinese Journal of Rock Mechanics and Engineering
基金
国家重点基础研究发展计划(973)项目(2011CB013500)
国家自然科学基金委创新研究群体科学基金资助项目(51121005)
国家自然科学基金资助项目(41202202)
关键词
岩石力学
岩爆
地质构造
微震监测
微震前兆
rock mechanics
rockburst
geologic structure
microseismic monitoring
microseismic indication
