高寒地区高速铁路桥梁下部结构模态参数的变化规律研究  

Study on Change Law of Modal Parameters of Bridge Substructure for High Speed Railway in Alpine Region

作　　者：闫宇智 战家旺[1] 张楠[1] 夏禾[1] 强伟亮 

机构地区：[1]北京交通大学土木建筑工程学院,北京100044

出　　处：《中国铁道科学》2017年第6期47-55,共9页China Railway Science

基　　金：国家"九七三"计划项目(2013CB036203);中国铁路总公司科技研究开发计划项目(2015G006-M);中央高校基本科研业务费专项资金资助项目(2016YJS111)

摘　　要：针对高速铁路多跨简支梁桥墩—梁间振动强耦合的特点,采用复合随机子空间模态分析方法和冲击振动试验法相结合的信号处理方法,对高寒地区高速铁路简支梁桥的下部结构在1个完整冻融循环周期内4次动力测试结果进行分析,并对桥梁下部结构的模态参数进行识别,分析冻融循环对桥梁下部结构模态参数的影响规律。结果表明:随着冻结深度的增加,桥墩各阶横向振动频率均会增大,且全桥横向交错振动频率的增大趋势最为显著,最大增幅达36.8%;墩身高度是影响桥梁下部结构模态频率的主要设计参数,墩高对全桥横向交错振动模态的影响大于全桥横向整体摆动模态,随着墩高的增加,全桥横向交错振动频率在3~9 Hz之间变化,全桥横向整体摆动频率在2~4Hz之间变化;冻融循环作用下地质条件对桥墩的模态频率几乎没有影响。According to the strong coupling between the pier and beam of multi-span simply-supported beam bridge for high speed railway,four dynamic tests were carried out on the substructure of simply-supported beam bridge for high speed railway during a whole freeze-thaw cycle in alpine region.Test results were analyzed by the signal processing method which combined complex stochastic subspace modal analysis method with impact vibration test method.The modal parameters of substructure were identified and the influence of freeze-thaw cycles on the modal parameters of substructure was analyzed.Results show that with the increase of freezing depth,the lateral vibration frequency of pier at each order increases.The increase tendency of the interlaced vibration frequency in the transverse direction of the whole bridge is the most significant,and the maximum increase is 36.8%.The pier height is the main design factor affecting the modal frequency of bridge substructure,and the influence of pier height on the interlaced vibration mode in the transverse direction of the whole bridge is greater than the overall transverse swing mode of the whole bridge.With the increase of pier height,the interlaced vibration frequency in the transverse direction of the whole bridge varies between 3~9 Hz and the overall transverse swing frequency varies between 2~4 Hz.The geological conditions under the action of freeze-thaw cycle have little influence on the modal frequency of bridge pier.

关 键 词：高寒地区 冻融循环 高速铁路 简支梁桥 下部结构 模态参数 

分 类 号：U443.2[建筑科学—桥梁与隧道工程]