三门峡黄河公铁两用大桥总体设计及创新

三门峡黄河公铁两用大桥为蒙西至华中地区铁路煤运通道跨越黄河的控制性工程,通行双线重载铁路、双线Ⅰ级铁路及6车道高速公路,全长5 663. 754 m,其中公铁合建段长1 762. 733 m。主桥采用(84+9×108+84) m连续钢桁结合梁,钢桁梁为3片主桁结构,中边桁中心距13. 6 m,每片主桁均采用无竖杆的三角形桁架,桁高15 m,节间长12 m。下层铁路桥面采用正交异性整体钢桥面板;上层公路桥面采用混凝土板与主桁结合的组合结构。钢梁材质采用Q370qE。设计活载合计473. 2 k N/m。桥墩采用圆端形门式空心墩,基础采用钻孔桩基础。主桥采用双曲面减隔震支座及合理的构造处理有效提高了结构抗震性能。钢桁梁采用顶推法施工,公路桥面板采用预制架设法施工。

Overall Design and Innovation of Sanmenxia Yellow River Rail-road Bridge

The Sanmenxia Yellow River rail-road bridge is a control project of the railway coal transport corridor from Mengxi to Central China across the Yellow River. It carries double-track heavy-haul railway,double-track I-grade railway and six-lane expressway with a total length of 5 663. 754 m. The length of the rail-road joint construction section is 1 762. 733 m. The main bridge is a continuous steel truss composite girder bridge with a span of(84+9×108+84) m. The steel truss girder is a three-piece main truss structure and the center distance between the middle truss and the side truss is 13. 6 m. Each piece of the main truss adopts triangular truss without vertical bar,the truss height is 15 m and the length of segment is 12 m. The lower railway deck is orthotropic integral steel deck,and the upper highway deck is a combined structure of concrete slab and main truss. The steel material is Q370 qE. The total design live load is 473. 2 k N/m. The pier is round end hollow structure and the foundation is constructed with bored piles. Hyperboloid seismic isolation bearings and reasonable structural treatment are adopted in main bridge,which effectively improves the seismic performance of the structure. The steel truss girder is constructed by incremental launching method and the highway deck is completed by precast erection method.