施工临时措施对中承式混凝土梁拱组合桥受力的影响  

Effects of Temporary Construction Measures on Half-Through Concrete Composite Arch Bridges

作　　者：杨东辉 李国平[1] 

机构地区：[1]同济大学桥梁工程系,上海200092

出　　处：《结构工程师》2010年第5期136-141,共6页Structural Engineers

摘　　要：三跨中承式预应力混凝土连续梁拱组合桥的拱脚截面是受力控制截面,不当的构造和施工措施往往会使其出现不利的受力状态;同时中墩基础的约束作用也使纵梁预应力效应下降,并加剧拱脚的不利受力。为改善梁拱组合桥在施工和使用阶段的受力状态,使用结构分析程序建立有限元模型,对不同的构造和施工措施进行比较分析。结果表明,在施工阶段拱座和承台之间设置临时滑动槽,允许拱座在施工阶段沿纵桥向能够滑动,可以减小拱脚截面弯矩,提高纵梁预应力施加效率。最后得出上述施工临时措施可以有效改善中承式混凝土梁拱组合桥施工和使用阶段受力的结论。The arch springing section is the controlling cross section of the three-span half-through pretressed concrete continuous composite arch bridge.If improper measures are adopted in construction,perilous stress and strain states will appear in the structure.Due to the restriction of the foundation under the mid-pier,prestresses in longitudinal beams will decline,which will also aggravate the stress and strain states of arch springings.In order to improve the stress states of the composite arch bridge both in construction stage and use stage,different measures and configurations were compared and analyzed by establishing finite element models through the structural analyzing system.It was observed that when a temporary groove is set between the arch support and the pile cap during construction which allows the structure to move in the longitudinal direction,the bending moments in the arch springing decrease,and the pretresses in the longitudinal beams increase.Finally,a conclusion was drawn that the temporary constuction measure mentioned above can improve the stress and strain states of the half-through concrete composite bridge effectively both in construction stage and use stage.

关 键 词：施工阶段 临时措施 中承式 预应力混凝土连续 梁拱组合桥 受力状态 Arch 使用阶段 施工措施 控制截面 拱脚 预应力效应 预应力施加 有限元模型 纵梁 约束作用 截面弯矩 结构分析 构造 拱座 

分 类 号：U441.5[建筑科学—桥梁与隧道工程] U448.22[交通运输工程—道路与铁道工程]