高速铁路跨度132m再分式简支钢桁梁设计研究

西成高铁上跨西宝高铁及福银高速公路,与西宝高铁夹角仅14.2°,建桥条件复杂,经方案比选后采用1-132 m再分式简支钢桁梁。本桥是西成高铁重难点控制性桥梁工程,是国内首座高速铁路铺设无砟轨道的最大跨度简支钢桁梁桥。对本桥的关键技术问题进行研究,详细介绍本桥的主桁结构形式、杆件尺寸、联结系、桥面系、主桁计算模型及其计算注意事项、主桁及桥面系计算结果、动力分析结果、预拱度的设置、施工方案等。研究结果表明:再分式钢桁梁有效提高结构刚度;采用的正交异性板结构设计参数合理可靠;通过采取梁端设置过渡梁的措施,满足无砟轨道高速行车的要求;桥梁的强度、刚度、疲劳及动力性能等均满足高速铁路规范的要求。

Design and Research on 132 m Span Re-divided Simply-Supported Steel Truss Girders for High-Speed Railway

Xi'an-Chengdu High-speed Railway crosses over Xi'an-Baoji High-speed Railway and Fuzhou-Yinchuan Expressway.The angle between it and Xi'an-Baoji High-speed Railway is only 14.2°.Due to the complex construction conditions,1-132 m re-divided simply-supported steel truss girder is adopted based on scheme comparison.This bridge is the key and difficult control project of Xi'an-Chengdu High-speed Railway,and the first simply-supported steel truss bridge of largest span with ballastless track for high-speed railway in China.The key technical problems of the bridge are studied,the main truss structure,the size of the rod,the longitudinal and lateral connection system,the deck system,the calculation model of the main truss and the matters needing attention,the calculation results of the main truss and the bridge deck system,the results of the dynamic analysis,the pre-camber setting and the construction scheme are introduced in detail.The results of the study show that the structural stiffness of the re-divided steel truss is effectively improved;the design parameters of orthotropic plates are reasonable and reliable;the requirements for high-speed driving on ballastless track are satisfied by adopting such measures as setting the transition beam at the beam end;the strength,stiffness,fatigue and dynamic performances of the bridge meet the requirements of the high-speed railway specification.