Study On Buffeting Analysis For Long-Span Steel Truss Arch Bridge In Completion Stage

With the development of material science, construction technology and engineering design, the span of modern long-span arch bridge has constantly increased. But with the increased span, wind-induced vibration problems will become more and more prominent, especially in the full-bridge operational phase of the longest and most important stage. So, it is very important for us to guarantee their safety and applicability . Buffeting is the biggest threat for the bridge's traffic safety and comfort on complete bridge status. Taking the Chaotianmen Yangtze River Bridge of Chongqing as the project background, the buffeting problems of large-span steel arch truss bridge at operational state are studied in this paper.The study is mainly focused on the following aspects:Firstly, the finite element method theory of the dynamical characteristic analysis is introduced in this paper . To simply the problem, this paper use space beam element to equal the parts of bridge.Secondly, the basic theory about buffeting and frequency-domain response spectrum analysis is introduced in this paper. The motion-excited aerodynamic force and buffeting force is obtained through the theory proposed by Scanlan. And the finite element and CQC analysis for coupled buffeting problems of large-span steel arch truss bridges is developed.Finally, Aeroelastic model tunnel tests of Chongqing Chaotianmen Yangzi River Bridge are carried out. Spire, fence and roughness element are used for simulating the wind environment of the bridge located site. Response of the main bridge and main girder for wind action is tested in operational stage at different wind direction. Based on the test data, the paper studies the buffeting problems of large-span steel arch truss bridge different from the other bridges at operational stage .