城市快速路跨铁路跨度160m三主桁钢箱组合梁桥设计

武汉雄楚大街新建高架作为城市快速路,高架桥要跨越南环铁路光谷站咽喉区及在建的地铁2号线南延线,受平面条件及路线纵断面限制,跨铁路高架桥需要160 m跨度,桥面至梁底的结构高度不超过2.5 m。设计新建1-160 m钢桁梁(不等高三主桁)+钢箱梁组合结构,桁架横联采用椭圆形横撑,不设斜撑,横撑与上下弦杆以高强螺栓连接。采用在铁路以外现场拼装,顶推施工跨越铁路的方法,减小对既有铁路的干扰。运用Midas软件建立由桁架梁单元与钢箱板单元组合而成的全桥整体模型进行静力分析、稳定及动力分析和施工阶段分析,并对节点板等局部结构进行有限元细部分析。桥梁布置和施工方法满足边界条件,造型美观,各项计算指标满足要求。

Design of Urban Expressway 160m Composite Box Steel Girder Bridge with Three Main Trusses over Railway

The project in Wuhan Xiongchu Street is to build a viaduct as part of the urban expressway.The viaduct is located in the throat area of Optics Valley subway station,crossing over the South Central Railway and the southern extension of Metro Line 2. Restricted by plane condition and line profile,the viaduct requires a 160-meter-span across the railway,and the structure height of the bridge deck to the bottom of the beam must be not more than 2. 5 meters. The new 160 m composite box steel girder bridge with three main trusses is surrounded by oval cross-braces without oblique braces. The cross-braces are conjoined to the truss by high-tensile bolts. The new bridge beside the railway is installed using the incremental launching method to minimize the disturbance to the existing railway. Midas software isemployed to establish whole model with truss beam elements combined with steel box board unit and to conduct static analysis,stability analysis,dynamic analysis and construction analysis. Local structures such as node board details are analyzed with finite element method. The bridge layout and construction method satisfy the boundary conditions,aesthetically pleasing and the calculating indexes.