虚拟激励法在香港青马悬索桥抖振分析中的应用(英)

Application of pseudo excitation method to 3-D buffeting analysis of the Tsing Ma long-span suspension bridge

青马悬索桥是香港新机场建设的中心工程，它对将新机场与香港岛和九龙的繁华商业区相连接起着关键作用．表述了一个全新的抖振分析方法，并利用这种方法对青马桥的抖振响应作了全面的研究．有限元理论和随机振动虚拟激励法相结合是新方法的主要特点．这种方法可以考虑振型间的耦合、结构不同部分间的相互作用、风场的非均匀性以及非均匀的结构性质等多种因素；同时由于使用了虚拟激励法使计算量降低到适合于常规工程分析的水平．这种抖振分析方法是通用的，可以推广到类似问题的求解．最后给出了青马桥的抖振分析结果并与传统方法进行了比较．

The Tsing Ma long-span suspension bridge is the central structureof Lantau Fixed Crossing, which links the commercial centers of Hong KongIsland and Kowloon to the Hong Kong's New Airport on Lantau Island. Anextensive study of buffeting response of the Tsing Ma Bridge has beensuccessfully carried out by a new formulation for 3-D buffeting analysis oflong-span bridges. The formulation is featured by a complete finite elementapproach and the pseudo excitation method. The dynamic coupling betweenmodes of vibration, interaction between components of the bridge, spatial andtemporal changes of wind speeds, and varying structural properties have beennaturally taken into consideration with the computational effort reduced to areasonable degree. The new formulation is so general that it can be readilyextended to similar problems. The new formulation is verified by comparisonwith the traditional method.