大型刚构-连续梁桥预应力张拉过程主梁应变的FBG跟踪监测  

The Synchronous Monitoring of Girder Strain during the Prestressing Construction of Long Span Rigid Frame-Continuous Beam Bridge Based on FBG Sensors

作　　者：张通[1] 欧进萍[1,2] 

机构地区：[1]哈尔滨工业大学土木工程学院,黑龙江哈尔滨150090 [2]大连理工大学土木水利学院,辽宁大连116024

出　　处：《沈阳建筑大学学报（自然科学版）》2009年第3期409-413,共5页Journal of Shenyang Jianzhu University：Natural Science

基　　金：国家自然科学基金重点项目(50538020)

摘　　要：目的为了验证光纤光栅传感器在大型桥梁工程监测尤其是施工监测中的精确性及可行性,探寻桥梁施工监测中的新型传感技术.方法基于东营黄河大桥全寿命监测的系统构架,将大量的光纤FBG传感器布设在该桥关键断面上,用以监测施工及运营阶段的结构应变及温度.在主梁纵向预应力张拉过程中,用光纤光栅解调仪及其配套数据采集设备,对控制点上的传感器的中心波长信号进行了跟踪采集,进而得到了测点的应变时程曲线.结果通过建立施工过程的有限元模型,将监测值与理论计算值进行对比,并对二者之间的相对误差进行分析.发现监测值与理论计算值基本吻合,二者之间的相对误差随着预应力钢束的增长而增大,但最大仅为11.4%.结论光纤FBG传感器监测精度较高,可用于大型桥梁施工过程的应变监测.The paper aims to verify the accuracy and feasibility of the application of FBG sensors in the engineering monitoring of large bridge, especially in the construction monitoring, and to explore new-type sensing technique applied in the construction monitoring of bridge. Basing on the life-cycle monitoring system structure of Dongying Yellow River Bridge, a great deal of FBG sensors are laid in the key sections of this bridge to monitor the strain and temperature in the phase of construction and service. During the construction of longitudinal prestressing of main girder, the signals of central wavelength of the some FBG sensors located in the controlling positions, are synchronously collected with the optical fiber grating demodulator and its accessories, and then the strain-time history curves are gained. Through setting up the finite element model of construction process, monitored values and theoretical values are compared, and the relative errors between them are analyzed. It is found that monitored values are basically accordant with theoretical values and the relative error increases with the elongation of the prestress pipeline but the max value is 11.4%. The conclusion shows that the measuring precision of FBG sensor is high and it can be applied in the strain monitoring of large bridges during the course of construction.

关 键 词：光纤传感器 布拉格光纤光栅 预应力 应变 监测 

分 类 号：U446.3[建筑科学—桥梁与隧道工程]