土木与岩土工程监测新技术——BOFDA的性能与特点

A Novel Technique for Civil and Geotechnical Engineering Monitoring:Performance and Characteristics of BOFDA

在实验的基础上对新型分布式光纤监测技术——布里渊频域分析技术(BOFDA)的感测性能进行了测试与分析,其空间分辨率可达20cm,测试精度可达±2με,测试重复性为±4με;通过与布里渊光时域分析技术(BOTDA)测试性能的比较,对BOFDA的测试性能进行了评价,分析了应变过渡区产生的原因;通过BOFDA等强度梁实验,并与电阻应变片测试结果和理论计算值比较,证明了BOFDA优异的测试性能。最后,对BOFDA在各类工程防灾减灾监测中可能遇到传感光缆的保护及温度补偿问题进行了分析,并提出相应解决方案。

In this paper,the performance of a novel technology—Brillouin optical frequency domain analysis（BOFDA）was tested and analyzed on the basis of experiments,and its spatial resolution,test accuracy and repeatability are 20 cm,±2×10-6 and ±4×10-6,respectively;Secondly,based on the tests,the comparison between brillouin time domain analysis and brillouin frequency domain analysis was conducted,and the reason of strain transition section was revealed.Thirdly,by comparing with traditional strain gauges measurements and theoretical calculations,we adopted the BOFDA to the equal intensity beam to verify the excellent test performance in the strain measurement.At last,the possible problem of BOFDA′s application in the monitoring of disaster prevention and mitigation project,such as temperature compensation and cable protection,was discussed and the corresponding solution is also presented.