基于BOTDA的混凝土结构裂缝识别试验研究及工程应用  

Experimental Study and Engineering Application on Identifying Cracks in Concrete Structure Based on BOTDA

作　　者：汪辛 丁志凯[4] 刘胜春[1] WANG Xin;DING Zhi-kai;LIU Sheng-chun(School of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China;China Highway Engineering Consulting Corporation,Beijing 100089,China;CHECC Highway Maintenance and Test Technology Co.,Ltd.,Beijing 100089,China;CCCC Second Highway Consultants Co.,Ltd.,Wuhan Hubei 430052,China)

机构地区：[1]北京交通大学土木建筑工程学院,北京100044 [2]中国公路工程咨询集团有限公司,北京100089 [3]中咨公路养护检测技术有限公司,北京100089 [4]中交第二公路勘察设计研究院有限公司,湖北武汉430052

出　　处：《公路交通科技》2023年第9期151-157,共7页Journal of Highway and Transportation Research and Development

基　　金：国家自然科学基金项目(61827817,61525501);北京市自然科学基金项目(4192022);内蒙古自治区科技计划项目(2021GG0304)。

摘　　要：为了研究BOTDA光纤传感技术用于混凝土结构裂缝监测的可行性,进行了高强钢筋活性粉末混凝土梁加载试验和公路隧道衬砌裂缝现场监测试验。通过在高强钢筋活性粉末混凝土梁的表面和内部同时布设分布式光纤,使用千斤顶施加多级荷载,获得了多级荷载作用下混凝土梁表面和内部的应变分布。通过对应变数据的分析,了解了混凝土梁从没有裂缝到出现裂缝以及裂缝发展全过程的应变变化规律。混凝土梁加载试验结果说明:基于BOTDA的光纤传感技术可以精准定位混凝土结构裂缝,而且光纤传感技术可以监测混凝土结构裂缝产生,发展全过程,满足全时全域的监测要求。在宜巴高速某隧道现场搭建BOTDA分布式光纤隧道衬砌裂缝监测系统,分析监测数据和现场实地勘察结果也验证了该系统用于监测裂缝产生,发展全过程的可行性。结果表明:裂缝产生的地方应变变化较大,应变差可达到800με以上,而且产生裂缝区域的应变差与没有产生裂缝区域的应变差相差较大,从应变差分布图中可以很明显地识别,建议后期将要建设的隧道衬砌的裂缝监测系统报警阈值设定为800με,若应变差超过800με,监测系统应进行报警,养护人员需要到现场进行查看并判断是否需要进行养护。In order to study the feasibility of using BOTDA optical fiber sensing technology for monitoring cracks in concrete structures,the loading test on high-strength steel reinforced reactive powder concrete beams and the on-site monitoring test on cracks in highway tunnel lining are conducted.By arranging distributed optical fibers on the surface and inside of high-strength reinforced reactive powder concrete beam,and applying multi-level loads with jack,the strain distributions on the surface and inside of concrete beam under multi-level loads are obtained.Through the analysis on the strain data,the strain variation pattern of concrete beam from no crack to the occurrence of cracks and the entire process of crack development are understood.The loading test result of the concrete beams indicates that the optical fiber sensing technology based on BOTDA can accurately locate the cracks in concrete structure,and the optical fiber sensing technology can monitor the entire process of crack generation and development in concrete structure,meeting the“full-time and full-domain”monitoring requirements.A BOTDA distributed optical fiber tunnel lining crack monitoring system is built at the site of a tunnel on Yiba Expressway.The feasibility of using this system to monitor the entire process of crack generation and development was also verified through analysis of monitoring data and on-site investigation.A BOTDA distributed optical fiber tunnel lining crack monitoring system was built on a tunnel site of Yicheng-Badong expressway.The monitoring data analysis and on-site investigation results also verified the feasibility of using this system to monitor the entire process of crack generation and development.The result shows that the strain changes greatly in the area where cracks occurred,with a strain difference of more than 800με,and the strain difference between the crack producing area and the non-crack producing area is significant,which can be clearly identified from the strain difference distribution curve.It is su

关 键 词：隧道工程 裂缝识别 布里渊光时域分析 光纤布设 应变 

分 类 号：U456.3[建筑科学—桥梁与隧道工程]