混凝土内部应变分布式光纤实时检测方法及试验研究

摘要

布里渊散射光时域分析技术(BOTDA)是1种新型光电监测技术,可对沿光纤轴向的应变、温度进行分布式监测,并具有长距离、分布式、高精度和耐久性等特点,适用于结构的健康监测.系统介绍了基于BOTDA的混凝土内部分布式应变的检测方法,并通过试验研究标定了由气吹再灌浆技术铺设的埋入式传感光纤的工作性能,解决了工程应用中无法将长距离分布式传感光纤埋入混凝土内部的技术难题.试验结果表明,以气吹再灌浆技术铺设的埋入式光纤传感器能有效检测混凝土内部分布式应变,可应用于结构物的全面、长期、稳定、实时的健康监测.%The Brilliouin optical time domain analysis (BOTDA) is a newly developed technique adopted to measure and monitor the strain and temperature generated along optical fibers. The BOTDA has the characteristics of distributed measurement, long distance, high precision and durability, so it is suitable to structural health monitoring. Then a new optical fiber sensor embedded method based on air-blowing and vacuum grouting is introduced. It can lay the long distance distributed optical fiber into the concrete easily in short time. An experiment has been set up to study the validity of the new method, which shows that the embedded optical fiber can measure the concrete strain accurately, and it can realize the comprehensive, long-term, stable and real-time health monitoring to the civil structure.