美国哥伦布高架桥受力分析及施工技术  

作　　者：王贵春[1] 李武生 

机构地区：[1]郑州大学土木工程学院 [2]河南省朝阳建筑设计院

出　　处：《世界桥梁》2014年第2期1-5,16,共6页World Bridges

摘　　要：哥伦布高架桥位于美国30号公路上,主桥为钢管混凝土系杆拱桥,拱肋采用钢管混凝土结构(拱肋间未设横撑),系杆采用预应力钢箱混凝土结构。为了解桥梁结构的受力性能,利用有限元软件建立该桥三维模型,考虑钢管、钢箱与混凝土的相互约束作用,分析拱肋和系杆的受力状况以及拱肋和系杆联结处的应力分布状况,同时校核拱的局部屈曲、横向稳定性和面内屈曲。分析结果表明:该桥拱肋不会发生局部屈曲,内充混凝土的约束效应使钢管的抗压强度明显增加,拱肋和系杆的受力及预应力钢丝束的设置合理,拱肋和系杆联结处的最大应力小于极限强度,结构不会发生横向失稳和面内屈曲。该桥施工时利用旧桥桥面板未拆除部分作为2个拱肋的组装和架设平台,在完成该桥的一半施工后,拆除旧桥剩余部分,利用已建成的桥面板作为施工平台,施工速度快,且对铁路交通的干扰较小。the preliminary study, four cable cranes should be employed to hoist and erect the steel box girder sections from the midspan of the two main spans towards the towers. The finite element method was used to establish the link element model of the bridge to do closure simulation calculation, based on which the required dragging forces for the closure under different conditions were obtained. The dragging and pre-offset setting system was designed in accordance with the calculation results. By scheme comparison and selection, the jacks were used to drag the already-erected gird- er sections to gain the pre-offset for the main girder closure. During the closing process, a 300 t jack was installed to each of the upstream and downstream tower legs. Each jack is equipped with 12 nos. Ф15.2 high-strength low-relaxation prestressing steel strands. Overhanging beams are in- serted into the manholes in the tower legs above the bridge deck to form the supporting seats of the jacks. The cable cranes hoisted the closure section vertically, when the net distance from the top of jacks to the bottom of the already-hoisted girder section was 20-30 cm, the dragging and pre-o{f- set setting system was used to drag the girder sections and widen the closure space to complete the closure section construction.

关 键 词：系杆拱桥 钢管混凝土结构 应力 屈曲 横向稳定性 约束效应 有限元法 施工技术 

分 类 号：U448.225[建筑科学—桥梁与隧道工程]