异型桥梁结构的优化分析

立交桥多属于跨线构造物,为满足道路线型要求,立交桥多包含有曲线异型变宽的桥型结构,其跨径组合往往不能按结构的合理跨径进行布置,使得桥梁的受力状态复杂。针对西安枣园路立交中的异型桥梁,拟定6种构型方案,应用梁格法理论构建其有限元模型,分析了在不同工况下6种构型的静力及基频,确定出最优方案,进而确定出该立交桥匝道的分叉点及分叉箱梁的长度。

Optimization Analysis of Heterotypic Bridge Structures

Generally,a flyover belongs to a crossing structure.To meet the alignment requirements of road,the most of flyovers are designed as the curve heterotypic widening structures.The span combination can not be often arranged according to the reasonable spans of structure so as to make the stress state of flyover complex.Aiming at the heterotypic structure of Xi'an Zaoyuan Road Interchange,six structural schemes are brought forward.The Finite Element Analysis(FEA) model of the schemes is set up based on beam-grid theory.The article analyzes the static stresses and basic frequencies of six structures at the different load conditions.The optimization scheme is determined so as to determine the bifurcate nodes and lengths of the interchange ramps.