纵横梁耦合连续体系在城市立交桥分合流位置处的应用分析  

Analysis on Application of Coupled Continuous System of Longitudinal and Transverse Beams at Junction of Urban Interchange

作　　者：汪浩 李京 WANG Hao;LI Jing

机构地区：[1]上海浦东建筑设计研究院有限公司,上海市201206

出　　处：《城市道桥与防洪》2024年第2期77-81,I0011,I0012,共7页Urban Roads Bridges & Flood Control

摘　　要：城市立交桥在分合流位置常通过采用异形钢结构桥梁,并设置伸缩缝的形式适应桥面宽度的改变。但对于日益增多的城市立交桥改扩建工程,分合流位置有时需要设置大型门架横梁跨越地下管网或构筑物,此时在该处设置伸缩缝会因主梁与横梁高度的叠加,导致结构高度过大。为研究该情况下的桥梁结构选型问题,提出在分合流位置采用纵横梁耦合的连续体系方案,借助有限元计算方法,对该类桥型的结构可行性进行分析,并讨论了支座横向偏心、门架横梁弯曲刚度对内力状态、整体刚度及支反力的影响,以期探明该类桥型的受力特点及关键力学参数。结果表明:恒载状态下的支反力均匀程度可作为控制性指标,检验该类桥型的受力合理性;适当增大门架横梁的弯曲刚度,可有效控制结构的竖向及扭转变形。At the junction of urban interchanges,the special-shaped steel structure bridges are commonly used and the type of expansion joint are set to adapt to the change of deck width.However,for the increasing urban interchange reconstruction and expansion projects,sometimes the large gantry beams need to be set at the junction positions to span the underground pipe network or structures.At this time,setting expansion joints at this place will lead to excessive structural height due to the superposition of the height of the main beam and the crossbeam,In order to study the selection of bridge structure in this case,a continuous system scheme of longitudinal and transverse beam coupling is proposed at the junction position.With the help of finite element method,the structural feasibility of this type of bridge is analyzed,and the effects of the lateral eccentricity of the support and the bending stiffness of the portal crossbeam on the internal force state,the overall stiffness and the support reaction force are discussed so as to find out the mechanical characteristics and key mechanical parameters of this type of bridge.The results show that the uniformity of support reaction force under the dead load can be used as a control index to test the stress rationality of this type of bridge.Properly increasing the bending stiffness of the portal crossbeam can effectively control the vertical and torsional deformation of the structure.

关 键 词：立交桥 分合流 门架横梁 伸缩缝 弯曲刚度 

分 类 号：U443.32[建筑科学—桥梁与隧道工程]