节段预制拼装桥梁“梁上运梁”仿真分析研究

Simulation Analysis of“Transporting Segments on Girder”in Segmental Precast Bridges

对于节段预制拼装桥梁,采用“梁上运梁”施工方案具有保护沿线生态环境、降低施工成本等优势。但是,会对施工期桥梁结构的受力安全性带来不利影响。文中以锡澄市域轨道交通工程35 m节段预制拼装简支箱梁标准跨为工程背景,给出节段预制拼装“梁上运梁”主要施工步骤。基于杆系有限元和实体有限元模型,对施工阶段桥梁结构的整体和局部力学性能进行仿真分析,并从经济性、施工工期等方面对“梁上运梁”和“梁下运梁”2种方案进行对比分析。结果表明,采用“梁上运梁”施工方案能够保障施工期结构受力安全的要求,并可节省成本。

For segmental precast bridges,the construction scheme of“transporting segments on girder”has the advantages of protecting the ecological environment along the line and reducing construction costs.However,it will have an adverse effect on the mechanical safety of the bridge structure during the construction period.Taking the 35 m standard span of segment precast and assembled simply supported box-girder in Xicheng urban rail transit project as the engineering background,the main construction steps of transporting segments on girder are proposed.Based on the beam and solid finite-element models,the overall and local mechanical properties of the bridge structure in the construction stage are simulated and analyzed.The two schemes of“transporting segments on girder”and“transporting segments under girder”are compared and analyzed from the aspects of economy and construction period.The results show that the construction scheme of transporting segments on girder can meet the requirements of structural stress safety during the construction period,and can save costs.