大跨径自锚式悬索桥受力分析

Mechanical analysis for long-span self-anchored suspension bridges

介绍主跨跨径为328m的自锚式悬索桥的结构形式和施工方法,并阐述其分析理论。针对主缆索的几何非线性,采用较为精确的分段悬链线法计算其空缆线形、成桥线形及无应力索长。然后,通过不同矢跨比和吊杆间距的比较以及预拱度的设置对自锚式悬索桥的受力特性进行了研究。根据恒载、移动荷载、制动力、支座沉降、风荷载和温度变化组合的7种工况,建立合理的力学模型对大桥进行仿真分析,采用有限位移法计算施工时的鞍座预偏量,主梁预拱度及营运阶段的应力、挠度和侧移。

In this paper, the structural configuration and construction method for a self-anchored suspension bridge with a main span of 328m are described and the analysis theory is also elaborated. The segmental eatenary method is adopted, by considering cable＇s geometrical non-linearity, to determine the alignment of cable under self-weight and static load, also to find the length of stress-free cable. The structural behavior of self-anchored suspension bridges is studied through the analysis of crucial parameters such as the rise-span ratio, the distance between hangers and girder camber. A mechanics model is constructed to carry out the simulation analysis, considering seven different load eases with various load combinations factors. The load eases are dead load, locomotive load, force due to braking, bearing settlement, wind force and temperature variations.