秦岭输水隧洞微震活动特征研究

Research on the Characteristics of Microseismic Activity in Qinling Water Diversion Tunnel

岩爆是深埋地下岩体工程中面临的世界性难题。针对秦岭输水隧洞岭南工程开挖过程中面临的岩爆问题,本文基于微震监测技术,分析了相邻洞段不同开挖方式、相同开挖方式不同洞段条件下的微震活动特征。结果表明:微震活跃性与岩爆风险高低密切相关,可作为岩爆防治的重要参考依据;埋深与岩性相近条件下,钻爆法比TBM法的微震能量相对更低,岩爆风险相对更低,但TBM法掘进效率更高;微震活跃性与开挖进尺、隧洞埋深不存在明显正相关性,围岩较好、微震活跃性较低时可适当增加掘进速度,提高开挖效率,当围岩变差、微震活跃性较高时宜适当降低掘进速度,延缓或降低岩爆风险。本研究结果可供类似工程岩爆防治和微震监测参考。

Rock burst is a worldwide problem in deep underground rock mass engineering. Aiming at the rockburst problem in the south of Qinling Water conveyance tunnel excavation, based on microseismic monitoring technology,this paper analyzes the microseismic activity characteristics of adjacent tunnel sections under different excavation modes and the same excavation mode under different tunnel sections. The results show that microseismic activity is closely related to rockburst risk,and it can be used as an important reference for rockburst prevention. Under the condition of similar buried depth and lithology,the micro-seismic energy and rock burst risk of the drilling and blasting method are lower than those of the TBM method,but the tunneling efficiency of the TBM method is higher. There is no obvious positive correlation between microseismic activity and excavation progress and tunnel depth. When the surrounding rock is good and the microseismic activity is low,the tunneling speed can be appropriately increased,and the excavation efficiency can be improved;when the surrounding rock is poor and the microseismic activity is high,the tunneling speed can be appropriately reduced to delay or reduce the rock burst risk. The results can be used as a reference for rock burst prevention and microseismic monitoring in similar projects.