摘要
现有光纤传感器的布设方法单一,无法完全适应各类工程的监测要求。为此,从实际工程桩体水平位移监测的需求出发,针对工程施工特点,设计单U型和多U型布设方法,并于室内构建PVC管简支梁模型,利用分布式光纤传感器对PVC管弯曲变形应变进行测量。采用各类应变组合进行挠度计算,分析了各应变组合挠度的试验误差。将上述两种光纤布设方法分别运用于实际工程的桩体水平位移监测中,并对比分析光纤传感器监测数据效果。试验与实际工程分析结果表明:利用分布式光纤计算桩体位移时,应当优先选用垂直基坑开挖面的双轴线应变进行计算,其次可利用其他轴线应变换算成基坑侧应变,进而用双轴线应变计算,而多轴线应变计算会造成多余误差;在实际工程运用时,分布式光纤传感器监测效果优于侧斜管监测效果。
Now available layout of optical fiber sensors has defects of single deployment,which could not meet demands of various projects.For this reason,according to the requirements of horizontal displacement monitoring of practical engineering pile,we develop a new single-U shaped and a multi-U shaped layout.Meanwhile,a simple supported beam of PVC pipe is designed,and its bending deformation and strain were measured by using distributed optical fiber sensor.The deflection of the pipe is calculated by different combination of strain,and the errors of each combination are analyzed.Finally,the above two optical fiber layout methods were applied to the actual engineering pile horizontal displacement monitoring,and the effect of optical fiber sensor monitoring data were compared.The experimental and practical engineering analysis show that when the distributed fiber is used to calculate the pile displacement,the double-axis strain being perpendicular to excavation face should be firstly used to calculate the pile displacement,and then the other axial strains can be converted into the lateral strain of the foundation pit,and further the double-axis strain can be used to calculate the pile displacement,while the multi-axis strain calculation will cause redundant errors.In practical engineering application,the monitoring effect of distributed optical fiber sensor is better than that of inclined pipe.
作者
朱栋梁
林伟宁
程贵海
陈秋平
赵伟来
陈国良
ZHU Donglian;LIN Weining;CHENG Guihai;CHEN Qiuping;ZHAO Weilai;CHEN Guoliang(School of Resources,Environment and Materials,Guangxi University,Nanning 530004,China;Jinhua-Yiwu-Dongyang Rail Transit Co.,Ltd.,Jinhua 321000,China;State Key Laboratory of Rock and Soil Mechanics and Engineering,Wuhan Institute of Rock and Soil Mechanics of CAS,Wuhan 430071,China)
出处
《人民长江》
北大核心
2022年第5期168-175,共8页
Yangtze River
基金
国家重点研发计划项目(2017YFF0108705,2017YFF0108706)。
关键词
基坑监测
围护结构
光纤传感器
光纤布设方法
位移计算
foundation pit monitoring
envelope structure
optical fiber sensor
layout method of optical fiber
displacement calculation
