5000m特大跨度悬索桥空气动力稳定性能理论研究

Theoretical research on the aerodynamic stability of super-longspan suspension bridge with a main span of 5000m

为研究5000m特大跨度悬索桥的三维空气动力稳定性能,首先实现了考虑竖向、侧向和扭转向三自由度自激力和静风荷载的三维全桥全模态颤振分析方法;其次根据风洞试验获得的气动参数对宽开槽和窄开槽两种方案进行了三维颤振性能分析,并与风洞试验和二维颤振分析结果进行了逐项对比,认为二维和三维颤振分析对于5000m悬索桥有可比性;然后实现了特大跨度悬索桥三维三重非线性静风性能分析方法,并对该方案进行研究发现5000m悬索桥的动力失稳先于静力失稳出现,静风稳定性能不控制设计。最终研究结论:从三维分析的角度看,中央开槽达到足够宽度的方案与窄开槽但设稳定板的方案都能给跨度达5000m的悬索桥提供足够高的颤振失稳临界风速,并能满足世界上绝大多数台风区的要求,5000m特大跨度悬索桥的设计由空气动力稳定性能控制。

Three dimensional aerodynamic stability performances of super long span suspension bridge with a main span of 5000m is studied by the following steps： Firstly,full mode flutter analysis method of super long span suspension bridge is developed by taking into account of the following effects,such as lateral,vertical and torsional self-excited forces and static wind loads.Then,numerical investigation is carried out using the previously described method to study the three dimensional flutter performances,and results from two dimensional and three dimensional approaches are compared in order to demonstrate their compatibility.Thereafter,three dimensions and three nonlinearities aerostatic stability analysis method are utilized to inspect the aerostatic stability of super long span suspension bridge,showing that 5000m suspension bridge is controlled by aerodynamic stability problems.Total conclusions can be drawn that both the wide slotted girder and narrow slotted girder with additional stabilizers can be feasible solutions for 5000m suspension bridge,which located in most of the typhoon prone areas around the world.