分布式光纤在桥梁监测中的应用研究

Research on application of distributed optical fiber in bridge monitoring

由于传统桥梁监测方案主要为点式测量,易造成漏检,可靠性低,若加密布设则造成工作量的成倍增加,且每次测量均需进行较长时间的现场准备工作,也难以实现远距离、大面积监测,因此亟需寻找一种更便捷和可靠的监测技术以弥补这些不足。基于PPP-BOTDA的分布式光纤传感技术具有精度高、测点多、可靠性强、抗干扰、耐腐蚀、测量范围广且可长距离监测等优点,发展潜力巨大,可广泛推广应用于各类岩土工程监测领域。依托汉江特大桥建设工程,采用传统监测方式与分布式光纤技术进行对比研究,结果显示光纤技术具有更精确的优势,也更能精确地反映出结构体内部各处的应变,证明了其实际应用中的可行性与优越性。

Due to the main method of traditional bridge monitoring is point measurement,and it leads to undetected error and low reliability easily. More measurement point cause more workload and preparation at present every time.Meanwhile,it is difficult for long-distance and extensive monitoring. Thus,it is urgent to develop a more convenient and reliable monitoring technology to make up for the deficiency. Distributed optical fiber sensing technology based on Brilouin optical time-domain analysis( BOTDA) have advantages of high precision,multi-points,high reliability,strong antiinterference,anti-corrosion,long-distance and extensive monitoring,thus there is a huge potential unrealized for various geotechnical engineering monitoring field. The traditional monitoring method is compared with distributed optical fiber technology based on the construction of Hanjiang Long Span Bridge. The results indicate that optical fiber technology have the advantage of higher precision and more precise reflection of strain in the structures. It proves feasibility and superiority of the distributed optical fiber technology.