采动影响下回采巷道锚杆安全状态监测研究

Research on safety status monitoring of anchor bolts in mining roadway under the influence of mining

针对高强度采动影响下巷道服役锚杆荷载实时状态监测的重要性和常规监测手段的局限性,以神东矿区布尔台煤矿综放工作面为工程背景,在室内对光纤光栅(FBG)传感器进行拉伸实验,验证其可行性,并通过现场试验获取FBG锚杆传感器实时监测波长数据,分析FBG锚杆传感器实时状态与回采巷道服役锚杆的轴力变化规律,进而基于现场监测数据分析巷道锚杆的实时安全状态。研究表明:锚杆轴力随着工作面接近,受矿压显现影响逐渐增大;回采巷道左帮锚杆杆体轴力变化明显,右帮锚杆杆体轴力变化较小;工作面推进到距锚杆60 m之后锚杆轴力迅速增加;左、右帮锚杆各位置的轴力具有不同的变化规律。回采巷道锚杆支护的实时监测为评估锚杆安全状态提供了技术支持。

Aiming at the importance of real-time load monitoring of the service bolt in roadway and the limitation of conventional monitoring methods under the influence of high-intensity mining,taking a fully mechanized caving face of Buertai Coal Mine in Shendong mining area as the engineering background,a tensile experiment was conducted indoors on the fiber Bragg grating(FBG)sensor to verify its feasibility.The real-time monitoring wavelength data of the FBG bolt sensors was obtained through on-site experiments,and the real-time status of FBG bolt sensors and the axial force variation pattern of service bolts in mining roadway were analyzed to obtain the real-time safety status of roadway bolts based on on-site monitoring data.The research shows that as the working face approaches,the axial force of the bolts gradually increases due to the influence of mine pressure;the axial force of the bolt body on left side of the mining roadway changes significantly,while the axial force value of bolt body on the right side changes relatively little;after the working face is advanced 60 m away from the bolts,the axial force increases rapidly;the axial force at each position of the rock bolts on the left and right side has different variation patterns.The real-time monitoring of bolt support in mining roadway provides technical support for evaluating the safety status of bolts.