基于能量法的下承式梁拱组合桥梁受力特性研究

Mechanical Behavior Study of Beam-Arch Hybrid Bridge Based on Energy Method

梁拱组合桥梁由拱、系梁和吊杆组合,组成构件多且各构件受力特性迥异,给力学分析带来很大困难.文章通过引入吊杆力相等、等效膜张力等假设,采用能量变分原理推导单跨下承式简支梁拱组合桥梁拱肋荷载分担比、主梁和拱肋跨中挠度的计算公式,从力学本质上揭示和分析不同结构设计参数对拱式组合体系桥梁整体受力性能的影响.可为设计人员在概念设计阶段确定较合理的结构参数提供理论依据.

The beam-arch hybrid bridge is the combination of the arch with girder and hanger rods.The analysis on mechanical behavior of this kind of bridges is very difficult due to the numerous combinations of construction members with different functions.Assuming equal tension force in each hanger rod and considered as a filmy tension force,the principle of energy variation is employed to establish the analytical solution of the load sharing ratio of the arch,the mid-span deflections of girder and arch,so as to reveal the influence of different design parameters on the structural mechanical behavior of the bridge.It helps designers to better understand the mechanical characteristics of beam-arch hybrid bridge and choose suitable structure parameters during the design stage.