基于光纤光栅传感技术的锚杆横向载荷识别方法与实验

Anchor transverse load identification method and experiment based on fiber optic grating sensing technology

锚杆被广泛使用于边坡及隧道等岩体支护中,锚杆的轴向应力、横向荷载与横向变形等信息是判断支护岩体安全的重要参数.本文基于光纤光栅传感技术,提出了一种测量锚杆横向荷载及横向变形的实验方法,该方法可满足传统锚杆轴向应变测量的功能需求,并新增测量锚杆横向荷载大小、方向和变形等功能.实验结果表明:横向荷载方向测量平均值最大误差为-0.48°,横向荷载测量值相对误差平均值最大为-4.2%.实验为光纤传感技术在锚杆监测领域的应用提供了新的可能.

Anchor rods are widely used for rock support,such as slopes and tunnels.Naturally,the information related to the axial stress,lateral load and lateral deformation of these anchors becomes important parameters for determining the safety of the supported rock mass.An experimental method for measuring the lateral load and lateral deformation of anchor rods based on fiber optic grating sensing technology is presented.It satisfies functional requirements of traditional anchor axial strain measurement,and adds functions of measuring the magnitude,direction and deformation of anchor transverse load.Experimental results show that the maximum error of the average value of the lateral load direction measurement equals-0.48°and the maximum relative error of the average value of the lateral load measurement equals-4.2%.Hopefully,our study can serve as a reference for the fiber optic sensing technology in the field of anchor monitoring.