Fully coupled buffeting analysis of Tsing Ma suspension bridge

Abstract

A fully coupled buffeting analysis of the Tsing Ma suspension bridge in Hong Kong is carried out in this paper. The features of the bridge, its natural frequencies and mode shapes from finite element analysis are first presented. Followed is an introduction to the formulation for fully coupled buffeting analysis of cable-supported bridges, which is featured mainly by a combination of finite element approach and pseudo-excitation method in the frequency domain. The buffeting response of bridge deck is then computed and compared with that from the conventional method. After the comparison, the effects from aeroelastic forces, multimodes and intermodes of vibration on deck response are examined. Finally, the buffeting response of the whole bridge is investigated with aerodynamic forces on not only bridge deck but also bridge towers and main cables. The results show that aeroelastic forces significantly affect the torsional response of the deck. The multimode responses are larger than single-mode responses in the vertical and torsional motions of the deck. The significant intermode responses may exist between the vibration modes of similar mode shapes or similar modal components. The buffeting of towers and main cables affects the lateral vibration of bridge deck and, in turn, the vibration of the bridge deck impacts the buffeting of the bridge towers and main cables.