重载铁路大跨度上承式钢管混凝土拱桥设计研究

对某重载铁路一座大跨度上承式钢管混凝土拱桥设计的桥梁布置、拱肋截面及线形、拱肋横撑形式、拱上桥墩方案、施工方法等若干关键问题展开研究,通过有限元对桥梁的承载力、刚度、自振特性等方面进行计算分析,得出以下主要结论:(1)上承式钢管混凝土拱桥能很好地适应桥址地形、地质条件;(2)拱肋采用四肢桁式截面,横向内倾6.5°,拱轴线形采用m=3.0悬链线,具有较好的受力性能;(3)腹杆采用H形钢构件,与拱肋弦管采用大节点连接方式,能满足重载铁路疲劳性能要求。(4)钢筋混凝土排架式桥墩在受力、景观等方面是最优选择。

Technical and Economic Comparison on Heavy Haul Railway Simply-supported Girder with High-Pier and Large Span

This paper focuses on the key issues of one concrete-filled steel tube deck plate arch bridge with large span on a heavy haul railway,including bridge layout,section and type of arch rib,arch rib horizontal support pattern,pier scheme and construction method. By using finite element method analysis of the bearing capacity,stiffness and vibration characteristics of the bridge,the followings are concluded:(1) concrete-filled steel tube deck plate arch bridge adapts well to the bridge site terrain and geological conditions;(2) the arch ribs adopts limb truss section,the transverse invert is 6. 5 °,and the arch axis adopts m = 3. 0 catenary with good mechanical properties;(3) the H-shaped steel member is used for the arch rib belly,and the connection of the arch rib chord with big node meets the fatigue performance requirement of the heavy-haul railway,and(4) reinforced concrete piers are the best choice in terms of the stress and landscape.