非对称超大跨度单线连续刚构设计与研究

研究目的:以新建铁路兰州至重庆线广元至重庆段的重点控制性工程朝阳嘉陵江右线大桥为例,对非对称超大跨度单线连续刚构的结构形式、结构受力情况、施工方法等进行具体分析和研究,为类似桥梁设计和施工提供参考。研究结论:(1)在桥墩设计时,采用纵向直坡,横向变坡的双壁墩,在保证结构有足够横向刚度的前提下可有效降低结构的纵向刚度,满足大跨连续结构的受力要求;(2)取消双薄壁中的横联,可使结构更轻盈美观;(3)在梁部设计时,优化纵向预应力的布置,取消腹板上弯束,依靠纵向预应力钢束和竖向预应力钢筋可克服主拉应力,避免大跨结构腹板的开裂。

Design and Research on Asymmetrical Super-large-span Single Track Continuous Rigid Frame

Research purposes: For construction of the Chaoyang River Bridge on the right track in the section between Guangyuan and Chongqing of the Lanzhou-Chongqing Railway,the analysis and research were made and done on the structural form,load bearing situation of structure and construction method for providing the reference to design and construction of the similar bridge. Research conclusions:The horizontal natural vibration period cycle was controlled because of the large span and narrow width of the beam’s box.Based on the analysis of the parameters,the analysis of the influences of the pier width,the box width of the beam,the slope of the pier and the horizontal layout of pile foundation on the natural vibration period of the structure were analyzed comprehensively.The double wall piers with the longitudinal straight slope and variation of lateral slope were designed to make sure the structure had enough lateral rigidity while the longitudinal stiffness of the could be reduced effectively,the requirement of load bearing for the large span continuous structure could be met,the transverse joint in double-wall piers could be cancelled and the structure could be of more lightweight with good looking appearance.In beam design,the layout of longitudinal prestressed steel strand was optimized,the upwardly curved steel strand in the web was cancelled,the principal tensile stress was overcome by the longitudinal steel strand and the vertical prestressed steel to avoid the crack of the web of large span structure.