天津滨海新区轨道Z4线双线U型截面简支梁桥的自振特性分析  

Analysis of Natural Vibration Characteristics of Double Track U-section Simply Supported Girder Bridge on Track Z4 in Binhai New Area of Tianjin

作　　者：黄欣[1] 张京京 赵静波[1] 石庆波 冀伟 HUANG Xin;ZHANG Jingjing;ZHAO Jingbo;SHI Qingbo;JI Wei(China Railway 11th Bureau Group Co.,Ltd.,Tianjin 300222,China;Lanzhou Jiaotong University,Lanzhou,Gansu 130017,China)

机构地区：[1]中铁十八局集团有限公司,天津300222 [2]兰州交通大学,甘肃兰州730070

出　　处：《水利与建筑工程学报》2021年第3期221-226,共6页Journal of Water Resources and Architectural Engineering

基　　金：天津市科技计划项目(18ZXGDGX00050)。

摘　　要：为研究双线U型截面简支梁桥的竖向弯曲振动频率,并获得一种简化的计算方法,以天津滨海新区轨道Z4线30 m双线U型截面简支梁桥为背景,采用理论分析和数值模拟相结合的方法对其动力性能进行研究。首先推导出考虑剪切和剪滞双重效应下,主梁和道床板的应变能求解公式,接着利用能量变分原理求得控制微分方程,最后运用Hamilton原理得到双线U型截面简支梁桥的竖向弯曲振动频率计算公式。为了验证所得竖向弯曲振动频率解析解的正确性,运用ANSYS与MIDAS/Civil有限元软件对双线U型截面简支梁桥进行数值模拟,求得双线U型截面简支梁桥的前三阶竖向弯曲振动频率,并将有限元结果与所推导的理论计算值进行对比。研究结果表明:竖向弯曲振动频率公式的计算结果与有限元结果吻合较好,精度较高;竖向弯曲振动频率受宽跨比变化的影响最大,道床板厚度变化次之,高跨比变化最小;且竖向弯曲振动频率随着宽跨比和道床板厚度的增大,均表现出增大趋势;随着竖向弯曲振动频率阶数的增高,其增幅均逐渐减小。In order to study the pure bending vertical vibration frequency of double track U-section simply supported girder bridge,and obtain a simplified calculation method,the dynamic characteristics of 30 m double track U-section simply supported girder bridge on track Z4 in Binhai New Area of Tianjin was analyzed by combining theoretical analysis with numerical simulation.For the double track U-section simply supported girder bridge,considering the shear deformation and shear lag effect,the strain energy formulas of web and track bed slab were derived respectively.The governing differential equations and boundary conditions were obtained by using the energy variational method.Finally,the pure bending vertical vibration frequency of double track U-section simply supported girder bridge was obtained by using Hamilton principle.In order to verify the correctness of the pure bending vertical vibration frequency,ANSYS and MIDAS/Civil finite element software were used to carry out numerical simulation of the double track U-section simply supported girder bridge.The first three orders of natural frequency of the double track U-section simply supported girder bridge were obtained,and the results were compared with the theoretical calculated value.The results show that the calculated values of the pure bending vertical vibration frequency derived agree well with the finite element values.The ratio of width to span and thickness of track bed slab have great influence on the vertical vibration frequency,and the vertical vibration frequency increases with the increase of width span ratio and track bed slab thickness.The higher the frequency order,the smaller the amplitude of natural frequency.The height-length ratio has little influence on natural frequency.

关 键 词：U型梁 竖向弯曲振动频率 能量变分法 剪切变形 

分 类 号：U441.3[建筑科学—桥梁与隧道工程]