基于力法的斜拉桥静力计算

Static Analysis of Cable-stayed Bridge Based on Force Method

斜拉桥是大跨度公路桥中常见的形式,也是由索、塔柱和主梁三部分组成,是一种桥面体系受压支承体系收拉的多次超静定结构。拉桥的内力计算目前一般基于数值模拟,而理论基础不足,通过结构力学中的力法,在索梁相交处将梁截断换成中间铰,中间铰处弯矩为力法未知量xi,计算出索梁相交处梁截面的弯矩,推导斜拉桥使用阶段中的内力,最终画出主梁的弯矩图及斜拉索的轴力,因为计算量较大,可利用FORTRAN语言编程,完成计算工作,得出精确的斜拉桥拉索内力及梁横截面的弯矩。

Cable-stayed bridge is a common form of long-span highway bridge,which is composed of cables,towers and main beams.It is a statically indeterminate structure with multiple times of tension and tension of bridge deck system under compression.Bridge’s internal force calculation is generally based on numerical simulation which lacks of theoretical basis.By the use of the theory of structural mechanics,replacing beam cut-off with intermediate hinge in the intersection of cable-beam,we can calculate the bending moment of beam section,get internal force in the process of using stayed-cable bridge by setting bending moment of Intermediate hinge to xi,finally Draw the bending moment diagram of the main beam and the axial force of the stay cable.In consideration of large amount of calculation,this paper use FORTRAN programming language to complete the calculation work.