基于温度补偿的光纤光栅井下锚杆受力动态监测技术

Fiber Bragg Grating Load Distribution Dynamic Monitoring Technology for Underground Bolt Based on Temperature Compensation

基于光纤Bragg光栅传感原理与技术,通过实验室力学标定试验建立光纤光栅反射波波长与锚杆轴向应力、温度的物理关系,构建基于温度补偿的光纤光栅测力锚杆受力动态监测技术;并在塔山矿进行井下光纤Bragg光栅测力锚杆受力动态监测试验。试验结果表明,光纤Bragg光栅反射波波长偏移量呈高度线性关系,相关系数达0.99,光纤光栅测力具备高测量精度;但与此同时,光纤Bragg光栅反射波波长对温度变化敏感,温度每升高1℃,光纤Bragg光栅波长大约增加59 pm。基于温度补偿的光纤Bragg光栅井下锚杆受力动态监测系统可实现锚杆工作状态的高精度动态监测。

Based on the principle of optical fiber Bragg grating sensing technology,physical relationship between reflection wavelength of fiber Bragg grating and bolt axial stress,temperature is established according to mechanical calibration laboratory test; bolt load distribution dynamic monitoring system for fiber Bragg grating based on temperature compensation is built and experimented in Tashan Coal Mine. Experimental results show that fiber Bragg grating reflected light wavelength and bolt axial stress has a high linear relation,and the correlation coefficient is 0. 99. Fiber Bragg grating has high measurement accuracy. Optical fiber Bragg grating reflective wavelength is sensitive to temperature changes; temperature rises per 1 ℃,optical fiber Bragg grating wavelength increases 59 pm. Fiber Bragg grating anchor force dynamic monitoring system based on temperature compensation can realize high precision dynamic monitoring of the anchor status.