重载铁路线梁偏心对小半径曲线桥梁性能的影响  

Influence of Eccentricity of Heavy Haul Railway Line Beam on Performance of Small Radius Curve Bridge

作　　者：何占元 HE Zhanyuan(Guoneng Shuohuang Railway Development Co.Ltd.,Cangzhou Hebei 062350,China)

机构地区：[1]国能朔黄铁路发展有限责任公司,河北沧州062350

出　　处：《铁道建筑》2023年第11期74-81,共8页Railway Engineering

基　　金：河北省重点研发计划(20375410D)。

摘　　要：以一座存在严重线梁偏心危害的小半径(400 m)曲线桥梁(专桥-2059)为研究对象,采用理论计算与现场试验相结合的方法,开展线梁偏心对曲线桥梁运营性能和承载能力影响分析,提出偏心超限整治对策,并结合运营性能参数分析偏心超限整治效果。结果表明:线梁偏心对桥跨跨中横(竖)向振幅、竖向加速度影响显著,且各参数指标均随偏心值的增大而增大;与原设计状况(向外偏心170 mm)相比,现状偏心值(向内偏心326 mm)对曲线桥梁抗弯、抗剪承载能力均有不利影响。桥梁抗弯、抗剪承载能力最大降幅分别为26.63%、25.99%;在最不利工况下,内主梁使用阶段剪力检定承载系数为0.986,小于规范要求值(1.0),说明桥梁抗剪承载能力安全储备不足;整治后桥跨跨中竖向加速度下降最显著,平均值降幅为45.88%,最大值降幅为40.30%,同时桥跨跨中横(竖)向振幅有较大下降,梁跨结构的承载能力满足设计要求。Taking a small radius(400 m)curved bridge(Special Bridge-2059)with serious eccentricity hazards as the research object,a combined method of theoretical calculation and on-site testing was used to analyze the impact of eccentricity on the operational performance and bearing capacity of curved bridges,and the effect of eccentricity over limit rectification was analyzed based on operational performance parameters.The results show that the eccentricity of the line beam has a significant impact on the transverse(vertical)amplitude and vertical acceleration of the bridge span,and all parameter indicators increase with the increase of eccentricity value.Compared with the original design condition(outward eccentricity of 170 mm),the current eccentricity value(inward eccentricity of 326 mm)has adverse effects on the bending and shear bearing capacity of curved bridges.The maximum reduction in bending and shear bearing capacity of bridges is 26.63% and 25.99%,respectively.Under the most unfavorable working conditions,the shear force verification bearing coefficient of the inner main beam during use is 0.986,which is less than the required value(1.0)in the specifications,indicating that the safety reserve of the bridge shear bearing capacity is insufficient.After rectification,the vertical acceleration in the middle of the bridge span decreased the most significantly,with an average decrease of 45.88% and a maximum decrease of 40.30%.At the same time,the horizontal(vertical)amplitude in the middle of the bridge span decreased significantly,and the bearing capacity of the beam span structure can meet the design requirements.

关 键 词：重载铁路 线梁偏心 现场试验 小半径曲线桥 运营性能 承载能力 整治效果 

分 类 号：U239.4[交通运输工程—道路与铁道工程] U448.35[建筑科学—桥梁与隧道工程]