五峰山长江大桥主桥总体设计

Overall Design of Main Bridge of Wufengshan Changjiang River Bridge

连镇铁路五峰山长江大桥主桥为主跨1092 m公铁两用钢桁梁悬索桥,按4线高速铁路+8车道高速公路设计,主缆跨度为(350+1092+350)m,加劲梁跨度为(84+84+1092+84+84)m。加劲梁采用大节段整体设计,由竖向、横向支座与纵向阻尼器支承,立面为华伦桁式,横断面为带副桁的直主桁形式,材质为Q370qE钢。该桥采用双层桥面布置,上、下层桥面均为板桁结合正交异性整体桥面,顶板与U肋之间采用了双面焊全熔透焊接,铁路桥面道砟槽面板采用轧制不锈钢复合钢板。主缆垂跨比1/10,直径1.3 m,索股混编,采用钢结构锚固系统;索鞍为铸焊结合式,主索鞍纵向分3块制造。桥塔采用门式框架混凝土结构,塔顶设计为“五峰”造型,基础采用桩基础,其中南塔基础为长短桩设计。北锚碇采用大型沉井基础,南锚碇采用不等深圆形地连墙基础。研究表明:大桥结构的静、动力性能满足高速列车行车的安全性与舒适性要求。

The main bridge of Wufengshan Changjiang River Bridge on Lianyungang-Zhenjiang High-speed Railway is a steel truss girder suspension bridge with a main span of 1092 m,which is designed to accommodate four high-speed rail tracks and eight highway lanes.The main cable suspends three spans,comprising lengths of 350,1092 and 350 m,and the superstructure contains five spans of 84,84,1092,84 and 84 m.Warren trusses can be seen from the elevation view,while the cross section of the stiffening girder incorporates subsidiary trusses and the members of trusses are straight.The trusses are made of Q370qE steel.The bridge has two floors formed of integral orthotropic plates.The top plate and U-ribs are welded by double-sided full penetration welding,and the ballast trough plates in the rail floor are made of rolled stainless composite steel plates.T he main cable,which is 1.3 m in diameter,with a sag-to-main span ratio of 1/10,contains hybrid strands and is anchored by steel anchorages.The cable saddle takes form by casting and welding,which was divided into 3 blocks longitudinally for the ease of manufacturing.The towers that are supported by pile foundations are concrete portal structures with"five peaks"crowns,and the foundation of t he south tower contains piles with different lengths.The north anchorage is mounted on large caisson foundation,while the south anchorage is seated on circle diaphragm wall foundation that consists of walls with different depths.Studies reveal that the static and dynamic performance of the structure can meet the riding safety and comfort demands of high-speed trains.