基于雷达信息与监测预警的隧道围岩大变形研究

针对公路隧道溶洞和孔洞的存在给围岩的稳定性控制带来不同程度的困难且围岩大变形极易发生而造成工程事故,采用探地雷达超前探测和监控量测,归纳分析隧道围岩大变形的异常特征,并进一步通过贵州省晴兴高速公路登攀隧道出口围岩大变形预警的工程实例进行验算,获得黔西南区强风化多孔玄武岩及下伏灰岩溶洞雷达图像特征:有充填物时反射波振幅在洞腔范围内衰减强烈,强弱相间;无充填物时反射波基本无衰减,存在中断、起伏和错动现象。围岩大变形监测以拱顶下沉为主,21d最大累计沉降值达到89.40mm,变形速率最大波动范围为14.66～0.64mm/d。应用此结论可以在围岩出现大变形时及时预警并采取控制措施,更好地为后续工程服务。

Tunnel large deformation of surrounding rock research based on radar information and monitoring warning

Aiming at the existence of caves and holes in high.way tunnel will cause difficulty for surrounding rock＇ s stability in varying degrees and it is prone to result in large deformation of surrounding rock, cause accident, the paper summarizes and analyzes the abnormal characteristics of tunnel large deformation of surrounding rock by advanced detection of ground penetrating radar and monitoring. Meanwhile, with the project of Qingxing highway Dengpan tunnel exit surrounding rock＇ s large deformation and warning, we obtain radar images＇ characteristics to highly weathered porous basalt and underlying limestone caves in southwest of Guizhou province： reflection amplitude attenuates strongly and strength of the white in filling caves and there is almost no attenuation but with the phenomenon of disruption, ups and downs and dislocation in inanition. On the other side, when large deformation of surrounding rock is mainly vault sedimentation, its maximum cumulative settlement is 89.40mm during 21 days and deformation rate fluctuates from 14.66mm to 0.64mm per day. With the conclusion, it should be warned and take control measures timely to service follow-up work when large deformation appears.