FBG锚杆测力计研制及现场试验

Development of anchor dynamometer of FBG and its field test

针对巷道锚杆载荷监测的重要性及常规监测方式的局限性,采用理论分析、实验室测试及现场试验的方法,以光纤布拉格光栅(FBG)为核心敏感器件,研制了一种新型光纤光栅锚杆测力计。锚杆测力计标定及性能测试表明,其具有良好的线性度、重复性和较高的灵敏度,灵敏度为57.25 pm/MPa,线性拟合系数为0.999 6。在沙曲矿14301轨道巷中构建了锚杆支护质量光纤光栅监测系统,对工作面开采过程中巷道2个测站的锚杆载荷变化进行实时在线监测。应用结果表明,测站1几乎不受工作面开采扰动的影响,仍保持初始预紧力的作用效果;测站2的锚杆载荷呈现为先稳定后增大最后减小的变化趋势,监测数据可作为巷道围岩稳定与控制的数据基础。监测系统具有本质安全、抗电磁干扰、可靠性高的优点,适合进一步推广应用。

In view of the importance of bolting load monitoring in roadway and the limitations of the conventional monitoring methods, a new anchor dynamometer of FBG was developed with the fiber Bragg grating（FBG） as a key sensitive component through theoretical analysis, laboratory test, and field test. The results of calibration and performance tests have shown that the sensor has a very good linear- ity, repeatability and high sensitivity, with a sensitivity coefficient of 57.25 pm/MPa and a linear fitting coefficient of 0.999 6. The FBG monitoring system of bolting quality was constructed at the track road- way #14301 of Shaqu Coalmine and the real time on-line monitoring of bolting load changes at two measuring stations was carded out during working face mining respectively. Application results have shown that the bolting load in the No. 1 station kept constant during working face mining, and thus the No. 1 station was not influenced by the working face mining, while the bolting load in the No.2 station presented a stable-increase-decrease trend during this period. The monitoring data can be used as the foundation for the stability control of surrounding rock. The monitoring system has the advantages of intrinsic safety, anti-electromagnetic interference, high reliability, and is suitable for further populariza-tion and application.