Research On Dynamic Characteristics And Seismic Behavior Of Long Span Cable-stayed Bridge

Long span cable-stayed bridge is characterized by its beautiful appearance, lower construction cost, well mechanical property and so on. It's considered as a most competitive style among the morden bridges. At present cable-stayed bridge with single slanted pylon become more and more popular, such as Batman bridge in Australia, Ebro bridge in Spania and so on. Because of it's special view and well mechanical property, these bridges are become masterpiece. In our country, cable-stayed bridge with single slanted pylon is few and the studies of these special bridges is also few. But considering it's important impact on our national economy, investigators and devisers should increasingly attach more importance to their dynamic behavior, and some typical dynamic matter of bridges, such as seismic response, wind induced vibration, coupled dynamic vibration between bridge and vehicle should not be ignored.This paper takes the long span cable-stayed bridge with single slanted pylon as engineering background. Author analyzes its dynamic characteristics and seismic behaviors using the finite element program, and abstract it as follows:1. Establish 3-D finite element model of this whole bridge, calculate its dynamic characteristics and comparing the theoretical and practical results of other bridges of such type, summarize dynamic characteristic of these bridges.2. Modify above model along with altering structural form or the constitution of the bridge, calculate the variety of dynamic character, analyze this factors which will affect, discuss appropriate ways to optimize the dynamic character.3. Applying the anti-seismic theory, the anti-seismic capability of long span cable-stayed bridge with single slanted pylon is analyzed by time-history analysis. Basing on the results of time-history analysis, the structure form of this bridge has been changed mainly centering on the style of the cable and the angle of the slanted pylon. And the results can be reference for other bridges of the same type on seismic resistance. The good and sound collocation style of the cross supports can be confirmed and used to serve for the practical engineering only after considering their effect on the dynamical characteristic and anti-seismic characteristic of the bridge.