桩板结构下穿既有高铁桥梁数值分析

Numerical Analysis of Existing High-speed Rail Bridges under the Pile-sheet Structure

基于常规的道路下穿既有铁路桥梁形式,通过对桩板结构结合普通路基段下穿既有铁路桥梁建立三维数值模型,计算分析两种道路结构形式对铁路桥梁的影响。结果显示,软基处理工况对铁路桥墩的影响较大,相邻桥墩承台沉降差超限。故对原设计提出优化建议后再次进行数值分析,得出下穿段全部采用桩板结构,或优化软基处理布置形式、施工工艺等会降低对铁路桥梁的影响,相比之下,建议优先选用桩板结构形式下穿既有铁路桥梁。

Based on the conventional road underpassing the existing railway bridge form,a three-dimensional numerical model is established for the pile-slab structure combined with the ordinary subgrade section underpassing the existing railway bridge,and the influence of the two road structure forms on the railway bridge is calculated and analyzed.The results show that the soft foundation treatment condition has a great influence on the railway bridge piers,and the settlement difference of the adjacent bridge pier caps exceeds the limit.Therefore,after putting forward optimization suggestions on the original design,numerical analysis is carried out again,and it is concluded that the pile-plate structure is adopted for all the lower passages,or the optimization of the soft foundation treatment layout and construction technology will reduce the impact on the railway bridge.In contrast,the suggestion is given priority.The pile-sheet structure is used to penetrate the existing railway bridge.