高速铁路无支座整体式刚构设计

Design of Integral Rigid-Frame Bridge Without Bearings on High-Speed Railway

为与相邻公路桥对孔布置并具有较优的结构性能,新建福州至厦门铁路泉州湾跨海大桥引桥采用多联(3×70)m无支座整体式刚构,该桥型全桥不设支座,边墩与中墩均与主梁固结形成整体刚构。该桥主梁采用预应力混凝土箱梁;墩高20~50 m,中墩采用实体墩或空心墩,边墩采用薄壁墩,相邻联边墩共用基础。通过在相邻梁端加装横向限位器、应用无砟轨道小阻尼扣件、边墩顶梁段采用两交界边墩临时固结后悬臂浇筑施工等措施较好地解决了梁端相对横向位移、轨道适应性及海上施工等问题。对该无支座整体式刚构桥结构性能进行分析,结果表明:其各项指标均满足规范要求,具有较好的经济性、抗震性能和景观效果。

To construct a bridge with spans parallel to an adjacent highway bridge and allow the bridge to have ideal structural property,the approach bridge of Quanzhou Bay Bridge on the newly-built Fuzhou-Xiamen Railway is designed as an integral rigid-frame strucutre with multiple continuous units of 3×70 m.No bearings are used,the side and intermediate piers are all fixed with the main girder,creating an integral rigid-frame structure.The main girder comprises of prestressed concrete box girders.The piers are 20 to 50 m long,among which the intermediate piers are solid or hollow piers,and the side piers are thin-walled piers.The side piers that stand at the junction of two adjacent units share foundations.The problems,like relative transverse displacement at girder ends,applicability of tracks and offshore construction,were properly resolved by taking a series of measures,such as adding transverse limiters,utilizing fasteners with small damping effect on ballastless tracks,casting the girder segments on tops of side piers in cantilevers after temporarily fixing the two side piers at the junction of adjacent continuous units.The structural property of the integral rigid-frame bridge without bearings was analyzed.The results show that all the indexes can meet the code requirements.The design fulfills the demands of economy,seismic resistance and landscape effect.