用于隧道变形监测的分布式光纤定点式布设监测误差测定研究  

Study on monitoring error of distributed optical fiber using fixed-point layout for tunnel deformation monitoring

作　　者：侯公羽[1,2] 李子祥 胡涛 周天赐[1] 肖海林 HOU Gong-yu;LI Zi-xiang;HU Tao;ZHOU Tian-ci;XIAO Hai-lin(School of Mechanics and Civil Engineering,China University of Mining and Technology,Beijing 100083,China;School of Mining Engineering,Xinjiang Institute of Engineering,Urumqi,Xinjiang 830091,China)

机构地区：[1]中国矿业大学(北京)力学与建筑工程学院,北京100083 [2]新疆工程学院采矿工程系,新疆乌鲁木齐830091

出　　处：《岩土力学》2020年第10期3481-3490,共10页Rock and Soil Mechanics

基　　金：中央在京高校重大成果转化项目(No.ZDZH20141141301);国家自然科学基金委员会与神华集团有限责任公司联合资助重点项目(No.U1361210);中央高校基本科研业务费(No.2009KL02)。

摘　　要：使用分布式光纤进行隧道变形监测,当采用定点的方式来固定传感光纤时,为了更灵敏地感测隧道变形,需要对锚固点之间的应变光纤进行预拉处理。在进行预拉的同时,光纤内部产生一定量预拉应变值,试验表明,施加不同的预拉量对该光纤的监测结果会产生一定的影响。为了减小光纤监测的误差,提高光纤的监测精度,根据感测光纤的应变特性、力学特性设计了光纤的张拉试验方案、构建了试验系统,进行了不同初始预拉值下的光纤张拉试验。通过对监测数据计算与分析,获得了两种特制传感光纤的最佳初始预拉值。结合以上研究成果,在北京市地铁8号线三期工程大红门桥站-和义站区间采用定点方式布设了传感光纤进行了监测。该研究结果可以为结构健康监测工程中传感光纤的布设问题提供参考。In order to detect tunnel deformation more sensitively, it is necessary to pre-stretch the strain optical fiber between anchor points when using fixed-point method to fix the sensing optical fiber. A certain amount of pre-tensile strain is thus generated inside the optical fiber due to the pre-stretching. Previous test results indicate that have shown that the monitoring results of the fiber will be affected by different pretension degrees. In order to reduce the monitoring error of optical fiber and improve the accuracy of monitoring, a scheme of optical fiber tension test was designed according to the strain characteristics and mechanical properties of sensing optical fiber, and a test system was then constructed to carry out the optical fiber tension test under different initial pre-tension values. By calculating and analyzing the experimental data, the optimal initial pre-tension values of two special sensing fibers were obtained. Combined with the above research results, the sensing optical fiber was applied in the Dahongmen Bridge Station–Heyi Station in the third phase of Beijing Metro Line No. 8. The results of this study can provide reference for the layout of sensing optical fiber in structural health monitoring engineering.

关 键 词：应变预拉值 光纤布设技术 BOTDR技术 地铁盾构隧道 

分 类 号：U25[交通运输工程—道路与铁道工程]