向莆铁路闽江特大桥主桥设计

Design of Main Bridge of Minjiang River Bridge of Xiangtang-Putian Railway

研究目的:根据向莆铁路闽江特大桥桥址处自然环境条件,跨越闽江主桥采用(60+7×100+60)m预应力混凝土连续梁桥式,梁部采用单箱单室直腹板变截面箱型梁,设置三向预应力体系。主桥桥墩采用圆端形实体墩,钻孔桩基础。通过对主桥结构进行平面静力分析、抗震设计、车桥耦合动力响应分析、桥上制动力计算分析,为该桥的设计提供依据,研究结果可供其他同类型桥梁参考。研究结论:梁体顶、底板正应力和腹板剪应力均能满足规范要求;38#、40#桥墩设置粘滞性阻尼器后,该桥结构满足抗震要求;主桥结构具有良好的动力性及列车走行性,列车通过桥梁时的安全性和乘坐舒适性均能满足要求。

Research purposes： In the light of the natural concrete continuous girder bridge with span arrangement of environment conditionts of the bridge site, the prestressed （60 ＋7 × 100 ＋60） m was adopted for the main bridge of Minjiang River Bridge of the Xiangtang - Puian Railway. A variable cross section box girder with single box, single chamber and vertical webs was adopted for the main girder of the main bridge with three - way prestresssing system. The piers of the main bridge were designed as the roundend solid piers, resting on the bored pile foundations. The softwares were used to analyze the plane static force, the seismic design of the main bridge structure, the train -bridge dynamic responses and the calculation of the braking force on deck of the bridge for providing the basis for the bridge design. The research results can be as the reference to the similar bridges. Research conclusions：The normal stress in top and bottom slabs of the girders and the shear force in weds could meet the relevant requirements in the codes. After adding the viscous dampers on the No. 38 and No. 40 piers, the structure could meet the seismic requirements. The main bridge structure had good dynamics with good traveling capacity for the train and it could meet the demands of the train running safety and passenger comfortableness.