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,确定出其各自的特性,进而分析了该立交桥匝道的分叉点位置及分叉箱梁长度的特点。研究方法可为同类结构的设计与施工提供参考,具有一定的工程应用价值。 The overpasses are mostly cross-line structures. To meet the requirements of road alignment, the overpasses often contain bridge-shaped structures with curve shaped widening. Their span combinations can not be arranged according to the reasonable span of the structure, which makes the bridge’s force state complicated . According to the special-shaped bridges in the Xi’an Zaoyuan Road interchange, six kinds of configuration schemes are drawn up, and the finite element model is established by using the theory of grillage method. The static and fundamental frequencies of the six kinds of configurations under different working conditions are analyzed, Characteristics, and then analyzed the overpass ramp bifurcation position and the characteristics of bifurcated box girder length. The research methods can provide references for the design and construction of similar structures and have certain engineering application value.