摘要
为探究环境激励下基于模态测试的无损检测方法评估古建筑桥梁结构刚度的可行性,以某跨径29 m的石拱桥为研究对象,依据有限元模型设计虚拟荷载试验,确定中载和偏载工况下满足工程精度要求的最少模态阶次;环境激励下采集石拱桥主梁的竖向振动信息并识别模态参数,进而识别结构的模态位移柔度矩阵;预测石拱桥在等效试验荷载作用下的模态挠度,与有限元模型设计挠度进行比较,计算挠度校验系数,结合现行规范评定桥梁刚度状况。结果表明,基于环境激励可以准确识别石拱桥的模态参数,中载工况下,只需2阶模态参数,偏载工况下,需要3阶模态参数预测的模态挠度便可满足工程精度要求;两种工况作用下,计算的桥梁跨中挠度校验系数均小于1,说明该石拱桥的实际状况较好;模态测试作为一种无损检测方法代替荷载试验评估古建筑石拱桥结构刚度具有较好的工程可行性。
In order to investigate the feasibility of a non-destructive testing method based on modal testing to assess the structural stiffness of ancient architectural bridges under environmental excitation,a 29 m span stone arch bridge was used as the research object,a virtual load test was designed based on the finite element model to determine the minimum modal order that meet the engineering accuracy requirements under symmetrical and eccentric load conditions;the vertical vibration information of the main girders of the stone arch bridge was collected under environmental excitation and the modal parameters were identified,and then the modal displacement flexibility matrix of the structure was identified;the modal deflection of the stone arch bridge under equivalent test load was predicted,compared with the design deflection of the finite element model,the deflection check factor was calculated,and the bridge stiffness condition was evaluated in conjunction with the current code.The results showed that the modal parameters of the stone arch bridge could be accurately identified based on the environmental excitation;the modal deflection predicted by the first two mode parameters could meet the engineering accuracy requirements under the symmetrical load condition and the first three mode parameters under the eccentric condition;the calculated mid-span deflection check coefficient was less than 1 under both conditions,which indicated that the actual condition of the bridge was better;modal testing,as a non-destructive testing method to replace load testing in evaluating the stiffness of ancient stone arch bridge structures,showed good engineering feasibility.
作者
赵若帆
亓兴军
郭冬梅
杨洪超
亓圣
Zhao Ruofan;Qi Xingjun;Guo Dongmei;Yang Hongchao;Qi Sheng(School of Traffic Engineering,Shandong Jianzhu University,Jinan 250101,China)
出处
《工业建筑》
2024年第10期223-229,共7页
Industrial Construction
基金
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)
山东省住房城乡建设科技计划项目(2024KYKF-CSGX024)
山东铁投集团科技计划项目(JQKJ2024-10)。
关键词
环境激励
拱桥
模态挠度
结构刚度
无损检测
environmental incentives
arch bridge
modal deflection
structural stiffness
nondestructive testing
