适用于高填方铁路路堤的装配式双层框架桥设计

Design for Prefabricated Double-layer Frame Bridge Suitable for High Fill Railway Embankments

当框架桥顶进下穿高填方铁路路基时,采用单层或一体式双层框架桥均存在诸多局限性,使得框架桥质量难以保证。为此,设计出一种适用于下穿高填方铁路路堤的装配式双层框架桥,由下部主框架桥与上部辅助框架桥组成;下部主框架桥与上部辅助框架桥可同步预制,施工质量可控,施工周期短,结构简单;通过角柱、后浇带和基于相邻预留孔洞的连接构件紧密相连,组装方便,组装后整体刚度大,稳定性强。受力分析表明:设置上部框架桥可大幅度减小下部主框架桥顶板和底板的弯矩值,从而可减小顶板和底板的板厚与配筋,为降低新建框架桥顶部高填方铁路路基的变形提供更多选择。

When the top of the frame bridge passes through the high filled railway subgrade,there are many limitations to using single-layer or integrated doublelayer frame bridges,and the quality of the frame bridge is difficult to ensure.For this purpose,a prefabricated double-layer frame bridge suitable for crossing high fill railway embankments is proposed,including a lower main frame bridge and an upper auxiliary frame bridge.The lower main frame bridge and the upper auxiliary frame bridge can be independently and synchronously prefabricated,with controllable construction quality,short construction period,and simple structure.Tightly connected through corner columns,post poured strips,and connecting components based on adjacent reserved holes,the assembly is convenient,and the overall stiffness and stability after assembly are high.Force analysis have shown that setting up an upper frame bridge can significantly reduce the bending moment values of the top and bottom plates of the lower main frame bridge,thereby reducing the thickness and reinforcement of the top and bottom plates.This provides more choices for reducing the deformation of the high filled railway subgrade at the top of newly constructed frame bridges.