自锚式斜拉-悬索协作体系桥基础微分方程近似推导

按连续体的方法描述自锚式斜拉-悬索协作体系桥在竖向荷载作用下的结构静力行为。基于分区广义变分原理,考虑了主梁和主塔的压弯耦合效应,建立了三跨自锚式斜拉-悬索协作体系桥的大位移不完全广义势能泛函,通过变分导出了自锚式斜拉-悬索协作体系桥的基础微分方程。以一座自锚式斜拉-悬索协作体系桥为例,求出其解析解,并与数值解相互比较,二者比较接近。所得基础微分方程可以用于自锚式斜拉-悬索协作体系桥的初步分析,并为阐述此类桥型的结构静力行为提供理论依据。

APPROXIMATE DEDUCTION OF THE BASIC DIFFERENTIAL EQUATIONS FOR SELF-ANCHORED CABLE-STAYED SUSPENSION BRIDGES

The static behavior of self-anchored cable-stayed suspension bridge is described with continuum method. Based on the partition generalized variational principle, the incomplete generalized potential energy functional of a three-span self-anchored cable-stayed suspension bridge is established by considering the coupling effect of flexural and axial action of the girder and the tower. The differential equations of self-anchored cable-stayed suspension bridge are derived through constraint variation. A self-anchored cable-stayed suspension bridge is taken as an example. The results from the proposed analytic method agreed well with those from numerical analysis. The differential equations can analyze self-anchored cable-stayed suspension bridge primarily, and can provide a theoretical basis for the static analysis of such bridges.