隧道洞口危岩落石监测技术及应用

Monitoring Technology and Application of Dangerous Rock and Rockfall at Tunnel Entrance

针对目前山区铁路危岩落石灾害监测相对滞后、误报率高的问题,对某山区铁路沿线26座隧道进行了现场调查。根据危岩体形成机理将沿线危岩体划分为陡坡危岩、陡坎危岩、斜坡活石堆、顺倾危岩和坡面孤石群五类。介绍了微震监测、智能监测网、被动防护网、三维激光异物侵限监测等监测技术的原理及存在的问题。将危岩成灾过程划分为五个阶段,依据各阶段危岩体发育特点指出监测重点,并建立了危岩落石监测预警体系。选取一隧道出口仰坡危岩体典型工点,通过两次现场调查查清危岩体分布及特征,并划分为四个风险区。从事前、事中、事后三个方面明确了监测技术和监测项目。根据危岩体位置和位移方向,Ⅰ区、Ⅳ区危岩体位移对铁路运营安全影响较大,应重点排查。

In response to the relatively lagging monitoring and high false alarm rate of dangerous rock and rockfall disasters on railways in mountainous areas,on-site investigations were conducted on 26 tunnels along a railway line in a certain mountainous area.According to the formation mechanism of dangerous rocks,the dangerous rocks along the railway line are divided into five categories including steep slope dangerous rocks,steep scarp dangerous rocks,slope live rock piles,inclined dangerous rocks,and slope solitary rock groups.The principles and existing problems of monitoring technologies such as microseismic monitoring,intelligent monitoring network,passive protection network,and three-dimensional laser foreign object intrusion monitoring were introduced.The process of dangerous rock disasters is divided into five stages,and monitoring focuses are identified based on the development characteristics of dangerous rock bodies in each stage.A monitoring and early warning system for dangerous rock and rockfall was established.A typical construction site for the dangerous rock mass on the uphill slope of the tunnel entrance was selected,two on-site investigations to investigate the distribution and characteristics of the dangerous rock mass were conducted,and four risk areas were divided.The monitoring techniques and monitoring projects have been clarified in three aspects,which are pre-engagement,during-engagement,and post-engagement.According to the monitored location and displacement direction of the dangerous rock mass,the displacement of the dangerous rock mass in ZoneⅠand ZoneⅢhas a significant impact on the safety of railway operation,and it is necessary to focus on investigation.