School of Mines, China University of Mining and Technology, Xuzhou 221116, China.
Research Center of Intelligent Mining, China University of Mining and Technology, Xuzhou 221116, China.
Sensors (Basel). 2022 May 23;22(10):3930. doi: 10.3390/s22103930.
Bolt-supporting technology has been widely used in mine roadway support, and its own working conditions have important reference value for roadway safety support. In order to realize the continuous and reliable monitoring of the bolt rod's working condition, this paper analyzes the existing problems of the existing fiber Bragg grating force-measuring bolt (FBG-FMB), and proposes a fiber grating strain desensitization sensing theory. Based on this theory, a desensitized FBG-FMB is developed with the spring as the elastic sensitive element. A mechanical analysis and drawing test show that the strain of the force-measuring bolt is greater than 60 times the micro-strain of the fiber grating, which verifies the feasibility of the structure design of the FBG-FMB. Finally, through the field application in the coal mine roadway, the working conditions of the bolt body at the two measuring points of the roadway are obtained to verify the reliability of the force-measuring bolt. In addition, the desensitized FBG-FMB can be widely used in the supporting fields of underground engineering such as slopes, tunnels, and foundation pits.
锚杆支护技术在矿山巷道支护中得到了广泛的应用，其自身的工作状况对巷道安全支护具有重要的参考价值。为实现锚杆杆体工作状况的连续可靠监测，本文分析了现有光纤布拉格光栅测力锚杆（FBG-FMB）存在的问题，提出了光纤光栅应变解敏传感理论。基于该理论，以弹簧为弹性敏感元件，研制了一种解敏光纤光栅测力锚杆。力学分析和拉拔试验表明，测力锚杆的应变大于光纤光栅微应变的 60 倍，验证了测力锚杆结构设计的可行性。最后，通过在煤矿巷道中的现场应用，获得了巷道两个测量点处锚杆体的工作状况，验证了测力锚杆的可靠性。此外，解敏光纤布拉格光栅测力锚杆可广泛应用于边坡、隧道、基坑等地下工程支护领域。
