温度对单箱三室箱梁动力特性影响研究  

Study on effect of temperature on dynamiccharacteristics of three-cell box girder

作　　者：刘钰 于鑫 潘旦光[1] LIU Yu;YU Xin;PAN Danguang(School of Civil and Resource Engineering,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]北京科技大学土木与资源工程学院,北京100083

出　　处：《中国测试》2024年第3期37-44,共8页China Measurement & Test

摘　　要：箱梁因其具有良好的结构特性被工程广泛应用。温度会对箱梁的动力特性产生影响,由温度作用产生的混凝土箱梁的应力和变形直接影响到混凝土结构的安全性、耐久性和适用性。为研究温度对箱梁动力特性的影响,对陕西沣河大桥进行不同温度情况下基于环境的模态识别试验研究。由于特殊原因,桥梁施工到当前位置需要暂停施工,因此进行动力特性试验时,桥梁处于封闭状态,从而可以避免外部干扰。通过试验得到结构的固有频率和模态,并将试验结果与有限元结果进行对比分析。在此基础上,进行箱梁动力特性和温度变化相关性的分析。研究结果表明,在短期范围内,温度对箱梁自振特性的影响并没有出现明显的正相关或负相关,温度的升高会使箱型桥梁结构温度更为不均匀,对其自振频率的影响更大且对低阶频率的影响更明显。The box girder is widely used in engineering because of its good structural characteristics.The temperature will affect the dynamic characteristics of the box girder.The stress and deformation of concrete box girder caused by temperature directly affect the safety,durability and applicability of concrete structure.In order to study the influence of temperature on the dynamic characteristics of the box girder,an experimental study of modal recognition based on environment was carried out upon Feng River Bridge in Shaanxi Province under different temperatures.Due to special reasons,the construction of the bridge needs to be suspended to the current position.Therefore,the bridge is in a closed state when the dynamic characteristics test is carried out,so as to avoid external interference.The natural frequencies and modals of the structure are obtained by experiments,and the experimental results are compared with the finite element results.On this basis,the correlation between dynamic characteristics of box girder and temperature variation is analyzed.The results show that in the short term,there is no obvious positive or negative correlation between the influence of temperature on the box girder's natural vibration characteristics.The increase of temperature will make the temperature of the box bridge structure more uneven,and the influence on its natural vibration frequency is greater and the influence on the low order frequency is more obvious.

关 键 词：单箱三室箱梁 温度 频率 模态 

分 类 号：U441[建筑科学—桥梁与隧道工程] TB9[交通运输工程—道路与铁道工程]