弱反射光栅滑坡监测系统的研究与应用

目前，光纤传感技术在桥梁、隧道、大坝等监测领域推广应用并取得了较好的效果，而基于弱反射光栅的FBG传感技术应用还处于起步阶段。针对BORDR和FBG技术应用于地质灾害监测中的限制，本文在介绍弱光纤光栅传感阵列监测技术原理的基础上，利用弱反射光栅传感阵列具有大容量、高精度的特点，设计了一款外定点式弱反射光栅传感光缆，并结合弱反射光栅传感阵列监测技术、物联网技术构建了基于弱反射光栅传感阵列的滑坡实时监测系统，开展了弱反射光栅传感光缆的室内实验并将弱反射光栅实时监测系统应用于滑坡监测实验中。监测系统测得158#-161#区域的连续4个弱反射光栅变形累加达到61.91mm，表明系统能准确定位滑坡发生位移变化的位置及监测滑坡位移的大小，实现了对滑坡地质灾害体的高密度的自动化准分布式监测。

Research and Application of Landslide Monitoring System based on Weak-reflection Fiber Grating Sensing Network

At present, fiber optic sensing technology is popularly used in the monitoring fields of bridges, tunnels and dams and has achieved good results, while the application of FBG sensing technology based on weak reflection grating is still in the initial stage. In view of the limitations of BORDR and FBG technologies in geological disaster monitoring, this paper introduces the principle of weak-reflection fiber grating sensor array monitoring technology and designs a kind of external fixed point weak-reflection grating sensing optical cable based on the characteristics of weak reflecting grating sensor array with large capacity and high precision. And then constructs a real-time landslide monitoring system by combining with weak-reflection grating sensor array monitoring technology and Internet of Things technology. This paper also carries out a calibration experiment of weak-reflection grating sensing optical cable and finally presents a field application experiment using the real-time landslide monitoring system. The monitoring system measured that the deformation of 4 consecutive weak reflection gratings from 158#-161# reached 61.91mm, which indicates that the system can accurately locate the location of the landslide displacement and monitor the size of the landslide displacement, realizing the high-density automatic quasi-distributed monitoring of the landslide geological hazard body.