基于微震监测技术的深埋长大隧洞群岩爆时空分布规律分析

Regularity of Spatio-Temporal Distribution of Rockburst in Deep-Buried Long Tunnels Based on Microseismic Monitoring Signals

以锦屏二级水电站深埋引(排)水隧洞群为工程背景,介绍了微震监测系统的组成,并根据隧洞工程的特点,优选出紧跟掌子面移动整体协同传感器优化布置方案;利用现场微震数据,探讨了微震事件和岩爆的时空相关性。研究结果表明:微震活跃及平静时段与岩爆显现频繁及稀少时段相吻合,微震事件和岩爆的空间分布规律相一致,表明微震事件时空演化规律与岩爆时空分布规律具有良好的相关性。通过分析和研究微震事件时空分布规律,可以对岩爆灾害进行有效预测,为岩爆防治提供科学依据。

The microseismic monitoring system used in the deep-buried diversion and drainage tunnels of Jinping-II hydropower station is introduced.An optimized layout of sensors working together with each other and keeping up with the movement of working face is proposed in line with the characteristic of tunnel excavation.The spatio-temporal evolution relation between microseismic event and rockburst is discussed.Results show that the active and quiet periods of microseismic activity coincide respectively with the frequent and rare rockburst-occurring periods,and the space distribution feature of microseismic events is similar to that of rockburst.The spatio-temporal evolution of microseismic events correlates well with the distribution features of rockburst.Therefore,it is possible and feasible to forecast rockburst disaster by the analysis and research on spatio-temporal evolution of microseismic events,which can provide scientific basis for rockburst prevention.