基于折面梁格模型的机场滑行道桥上部结构受力分析

Force Analysis for Superstructure of Airport Taxiway Bridge Based on Fold-surface Beam-grid Model

滑行道桥是大型机场中解决联络滑行道与陆侧交通立体交叉的一种特殊桥梁结构,其主要特点为宽桥面、大宽跨比、重型荷载。以一座上部结构为单箱多室连续箱梁的滑行道桥为例,建立了折面梁格模型,分析活载的空间效应、剪力滞效应及横梁受力。结果表明:箱梁分析时常用的采用单梁模型、利用偏载系数的分析方法不能准确反映超宽箱梁的空间受力特征;常用的横梁分析方法亦难以得出真实的横梁受力情况;建立折面梁格模型能够为设计提供准确的受力分析结果,是一种较为实用可靠、适用于超宽箱梁的分析方法。

An airport taxiway bridge is a special bridge structure to solve the interchange between the contact taxiway and the landside traffic in large airports. Its main characteristics are the bridge deck is wide,t he ratio of width/span is large,and the load is heavy.Taking a taxiway bridge with the superstructure of a single box and multi-compartment continuous box girder as an example,a fold-surface beam-grid model was established,and the space effect of live load,shear lag effect and crossbeam force were analyzed. The results show that the commonly used single beam model and the analysis method of eccentric load coefficient cannot accurately reflect the spatial stress characteristics of an ultra-wide box girder.It is also difficult to get the actual condition of crossbeam force using the common crossbeam analysis method.However, it is a reliable and practical analysis method for ultra-wide box girder through the fold-surface beam-grid model,which can provide accurate force results for the bridge design.