基于模态测试的曲线钢箱梁桥承载能力评定  

Evaluation of bearing capacity of curved steel box girder bridge based on modal testing

作　　者：王福祥 刘近龙 亓兴军 张瀚升 赵若帆 WANG Fuxiang;LIU Jinlong;QI Xingjun;ZHANG Hansheng;ZHAO Ruofan(School of Transportation Engineering,Shandong Jianzhu University,Jinan 250101,China;Shandong Construction Engineering Quality Inspection and Testing Center Co.,Ltd.,Jinan 250031,China;School of Civil Engineering,Shandong Jianzhu University,Jinan 250101,China)

机构地区：[1]山东建筑大学交通工程学院,济南250101 [2]山东省建筑工程质量检验检测中心有限公司,济南250031 [3]山东建筑大学土木工程学院,济南250101

出　　处：《黑龙江工程学院学报》2025年第2期17-24,共8页Journal of Heilongjiang Institute of Technology

基　　金：山东省住房城乡建设科技计划项目(2024KYKF-CSGX024);济青高速铁路有限公司科技计划项目(JQKJ2024-10);山东省交通运输厅科技计划项目(2022B06);山东省企业技术创新项目(202250101726,202160101415)。

摘　　要：以跨径组合为2×30 m的曲线钢箱梁桥为研究对象,对其进行静载试验和环境激励模态测试试验,利用加速度传感器采集桥梁结构的竖向加速度时程数据,采用SSI、EFDD等方法识别桥梁模态参数,用Kriging插值法对桥梁实测振型进行模态扩展,预测曲线梁桥在静载试验等效车辆荷载作用下测试截面的模态挠度,与实测静载挠度对比,计算结构校验系数,评估曲线梁桥承载力。依据共轭梁理论计算与位移振型相对应的应变振型,计算应变柔度矩阵,预测结构模态应变,与实测静载应变对比。结果表明,利用Kriging插值法获得的模态扩展振型能够精确地预测桥梁的模态挠度,与实测静载挠度相比,测试截面的相对误差不超过11%,基本满足工程精度的要求;基于环境激励模态参数识别预测的模态挠度,可代替静载试验的实测静载挠度评估桥梁的实际承载能力;通过应变柔度矩阵预测的桥梁模态应变与实测静载应变对比相对误差在12%左右;实验证明基于模态测试的曲线钢箱梁桥承载能力评定方法只需对桥梁结构进行模态测试即可实现对桥梁承载力的快速评定,该方法具有较好的准确性和实用性。The study focuses on a 2×30 m curved steel box girder bridge with a span combination,conducting static load tests and environmental excitation modal testing.Acceleration sensors are used to collect the vertical acceleration time history data of the bridge structure,and modal parameters of the bridge are identified using SSI,EFDD,etc.The measured modal shapes of the bridge are extended using Kriging interpolation,and the modal deflections of the test section under the equivalent vehicle load of the static load test are predicted.The structural verification coefficient is calculated by comparing the predicted modal deflections with the measured static load deflections,and the bearing capacity of the curved girder bridge is evaluated.The strain shape corresponding to the displacement shape is calculated based on the conjugate beam theory,and the strain flexibility matrix is computed,predicting the modal strain of the structure.The predicted modal strain is compared with the measured static load strain.The results show that the modal deflection predicted by the Kriging interpolation-based modal shape extension is highly accurate,with the relative error between the predicted and measured static load deflections not exceeding 11%for the test section,which meets the engineering precision requirements.The modal deflection predicted by the environmental excitation modal parameter identification and prediction can replace the measured static load deflection in evaluating the actual bearing capacity of the bridge.The relative error between the predicted and measured static load strain is about 13%for the strain predicted by the strain flexibility matrix.The experimental results show that the method of evaluating the bearing capacity of curved steel box girder bridges based on modal analysis only requires modal testing of the bridge structure to quickly assess the bearing capacity of the bridge.This method has good accuracy and practicality,and has broad application prospects.

关 键 词：模态挠度 静载试验 模态应变 KRIGING插值 校验系数 

分 类 号：U446.1[建筑科学—桥梁与隧道工程]