徐盐高铁盐城特大桥主跨312 m钢桁斜拉桥总体设计

徐盐高铁盐城特大桥为全线控制性工程,主桥横跨新洋港,采用跨度布置为(72+96+312+96+72) m的双塔双索面连续钢桁梁斜拉桥,半漂浮体系、塔梁之间设置阻尼器及速度锁定装置。主梁采用2片主桁,三角形桁式,桥面为正交异性板整体钢桥面,道砟槽范围内采用热轧不锈钢复合钢板。桥塔为H形花瓶式混凝土塔,塔座以上全高123 m,交接墩和辅助墩采用拱形双柱式门式墩。全桥共设置48对环氧平行钢丝斜拉索,平行索面,呈扇形布置,在塔端采用齿块锚固,在梁端采用锚拉板锚固。考虑施工期间台风影响周期较长且强度较大,利用桥址特点,边跨钢梁采用支架法架设,主跨钢梁利用桥面架梁吊机单向悬拼架设,并配合有效的抗风措施,大幅提高了施工过程中的结构抗风稳定性。

Overall Design of Steel Truss Girder Cable-Stayed Bridge with 312 m Main Span of Yancheng Extra Large Bridge on Xuzhou-Yancheng High-speed Railway

Yancheng Extra Large Bridge on Xuzhou-Yancheng High-speed Railway is the controlling project of the entire line. The main bridge adopts semi-floating system continuous steel truss cable-stayed bridge with double pylons and double cable planes. The span arrangement is(72+96+312+96+72) m. Viscous dampers and shock transmission units are set between towers and beams. The main girder employs two main trusses and one triangular truss. The integral steel structure deck uses orthotropic steel plates and hot-rolled stainless steel clad plate is used in the range of ballast groove. The towers are H-shaped vase concrete towers with the total height of 123 m above the tower pedestal. Arch double-column portal piers are used for the transfer pier and assistant pier. A total of 48 pairs of epoxy parallel steel wire stay cables are arranged in a fan-shape and anchored in the saw tooth block at the tower and in the anchor plate at the steel girder. On account of the long period and high strength of the typhoon during the construction, steel girders of side span are erected by bracket method and steel girders of the main span are erected by single-way suspension with deck derrick crane according to the characteristics of the bridge site, which, assisted by series of precaution measures, improves greatly the wind-resistance stability of the structure during the construction.