基于微震监测的TBM掘进工程岩爆预警研究

Study on rockburst early warning in TBM excavation engineering based on microseismic monitoring

为验证微震监测在TBM掘进工程岩爆预警中的可行性,以及研究TBM掘进工程围岩岩爆特征,采用新型微震监测系统在天山胜利隧道中的监测微震活动,对岩爆灾害进行预测预警。该系统既具有人工分析的准确性,又具有云服务平台的实时分析预警功能,其中对微震事件的定位精度在5~10 m左右。岩爆风险等级预测标准采用微震事件能量、矩震级、数量等多重评价指标,现场监测到的微震事件时序规律显示,最大能量的演化与最大矩震级的演化具有正相关关系。现场岩爆信息统计结果表明,天山胜利隧道岩爆一般发生在岩体从TMB盾尾揭露出来2 d后,属于时滞型岩爆。应用案例表明,基于微震监测的岩爆预测预警能够较好地服务于TBM掘进工程的安全施工。

To validate the feasibility of the microseismic monitoring in the early warning of rockburst in TBM excavation engineering,and to study the rockburst characteristics of surrounding rock,a newly developed microseismic(MS)monitoring system was employed in the Tianshan-Shengli tunnel to detect MS activities,and then to predict and warn the rockburst disasters.The system not only has the advantages of accuracy of artificial analysis,but also has the real-time analysis and early warning function of cloud service platform,of which positioning accuracy for MS events is about 5-10 m.The prediction criterion of rockburst risk level adopted multiple evaluation indexes such as energy,moment magnitude and quantity of MS events.It reveals that the evolution of maximum energy has a good positive correlation with that of maximum moment magnitude,through analyzing the monitored MS events.According to the field statistical results of rockburst information,the rockburst generally occurs two days after the rockmass is exposed from the tunnel boring machine(TBM)tail shield,which belongs to the delayed rockburst.The preliminary application cases indicate that the rockburst prediction and early warning based on MS monitoring can serve the safety construction of TBM excavation project well.