巷道围岩失稳监测技术及应用

Monitoring technology of roadway surrounding rock instability and its application

巷道围岩稳定性监测可及时对巷道变形与失稳做出预警,是保障煤矿安全的重要手段。针对巷道变形失稳监测的实际,构建45°倾角层状巷道相似模型,设计了可进行巷道围岩力学信息实时探测的小型普通与恒阻监测锚杆,进行基于恒阻大变形锚杆受力的巷道变形与失稳监测模型实验,同时进行多种倾角岩层巷道变形与失稳监测的离散元数值模拟,实验得到巷道变形破坏全过程的位移场精确量测信息与锚杆力学监测信息,分析巷道变形破坏机理,根据巷道变形与锚杆受力变化的时序特征,研究围岩失稳判别条件。结果表明:恒阻锚杆可实现巷道变形与失稳全过程监测,巷道围岩失稳的锚杆受力监测前兆信息为监测曲线短时间内显著持续上升,锚杆受力监测效果优于位移监测。研发恒阻锚杆受力巷道稳定性监测系统并在深部层状岩巷矿井进行工程应用,效果良好。

The stability monitoring of roadway surrounding rock can timely predict the deformation and instability of roadway, and it is an important means to ensure the safety of coal mine. In view of the fact that the monitoring of roadway deformation instability, a similar model of 45 degree dip roadway is constructed, the monitoring device of axial force in small bolt(SB) and small constant resistance bolt(SCRB) is designed to the real-time detection of roadway mechanics data, the model experiment of roadway deformation and instability monitoring based on SCRB is carried out, discrete element method is used to simulate the deformation and instability monitoring of various inclined strata roadways, the accurate measurement information of the displacement field and the mechanical monitoring information of the bolt are obtained, the deformation and failure mechanism of the roadway are analyzed. According to the time series characteristics of the deformation of the roadway and the force change of the anchor bolt, the criterion of instability of surrounding rock is studied. The SCRB can realize the whole process of roadway deformation and instability, the stress monitoring curve of the anchor rod obviously rises continuously in a short time, which is the precursor information of the instability of the surrounding roadway rock, the effect of mechanical monitoring of bolt is better than displacement monitoring, roadway stability monitoring system is developed and applied to the deep bedded rock roadway and excellent results have been achieved in its practical application.