大跨长联公铁两用连续钢桁梁桥成桥阶段温度效应研究  

Thermal Effect on Continuous Steel Truss Girder Rail-cum-Road Bridge with Long Spans and Units After Completion

作　　者：孟令强 郭传臣 姜永彪 MENG Lingqiang;GUO Chuanchen;JIANG Yongbiao(Tiezheng Testing Technology Co.,Ltd.,Jinan 250014,China;China Railway 14th Bureau Group Co.,Ltd.,Jinan 250101,China)

机构地区：[1]铁正检测科技有限公司,山东济南250014 [2]中铁十四局集团有限公司,山东济南250101

出　　处：《世界桥梁》2023年第4期77-84,共8页World Bridges

基　　金：国家自然科学基金面上项目(52075397);山东省企业技术创新项目(201930701027)。

摘　　要：针对公铁两用连续钢桁梁桥成桥阶段由上层公路桥面板遮挡引起的日照温差问题,以某公铁两用连续钢桁梁桥为背景,沿墩顶梁截面竖向及横向布置温度测点实测桥梁温度场,采用分段函数拟合得到梁截面横、竖向温度梯度,建立成桥阶段有限元模型,分析均匀温度作用与温度梯度作用对桥梁线形及应力的影响。结果表明:实测温度场的桥梁横、竖向温度梯度与太阳辐射强度、杆件所处位置以及照射时间有关;与温度梯度作用相比,均匀温度作用中整体降温对桥梁结构线形影响更为不利;与均匀温度作用相比,温度梯度作用对桥梁边跨墩顶附近边桁下弦杆局部应力影响更为不利;中跨墩顶附近中桁上弦杆受公路桥面板的遮挡,杆件温度较低,温度梯度作用影响较小。The study in this paper focuses on the temperature difference issue caused by solar shielding effect of the upper roadway deck in the continuous steel truss girder rail-cum-road bridge.An existing continuous steel truss girder rail-cum-road bridge is used for a case study.Measurement points were placed along the depth and width of the pier-top trusses to obtain the real temperature field of the bridge.Piecewise function fitting was carried out to attain the transverse and vertical temperature gradients of the girder cross-section.The influence of uniform thermal effect and temperature gradients on the bridge alignment and stresses after the completion of the bridge was numerically analyzed.It is shown that the transverse and vertical temperature gradients of the measured temperature field of the bridge are associated with the solar radiation intensity,locations of truss members and solar exposure period.Compared with temperature gradients,the overall temperature falling related to uniform temperature effect is more adverse to the bridge alignment.Compared with the uniform temperature effect,temperature gradients are more adverse to the local stresses in the lower chords of edge trusses in the vicinity of pier top in side spans.For the upper chords near pier-top central truss in the intermediate span,the shielding effect of the roadway deck makes the temperature of the members lower,but the effect of temperature gradients is minimal.

关 键 词：公路铁路两用桥 钢桁梁桥 成桥阶段 均匀温度作用 温度梯度作用 线形 应力 有限元法 

分 类 号：U448.211[建筑科学—桥梁与隧道工程] U441.5[交通运输工程—道路与铁道工程]