The Liujiaxia Suspension Bridge Wind-induced Vibration And Three-dimensional Non-uniform Excitation Seismic Analysis

With the continuously strengthened China’s overall national economic construction has made noteworthy achievements, the National Transportation modernization process to speed up China’s bridge construction has been developing rapidly.However, high winds, earthquakes and other natural disasters increased, the structure, especially the safety impact of long-span bridges has become increasingly prominent.This paper base on the background of The Liujiaxia suspension bridge, and its main span of536m single-span simply supported suspension bridge. Using the general-purpose finite element software to study the wind-resistance cable on the seismic structure of wind-induced vibration effect and the role of three-dimensional multi-support excitation. The specific studies are as follows:(1) First introduced the course of development of domestic and foreign suspension bridge, and the process of building wind and seismic theory of long span suspension bridges.(2) Then introduce the dynamic theory of long span suspension bridges, including the basic differential equations of free vibration of suspension bridge, suspension bridge fr-ee vibration of three-dimensional finite element analysis theory, the long span suspens-eon bridges wind-induced vibration theory, the seismic excitation model and the seism-ic responsetheory.(3) Based on the Liujiaxia large span suspension bridge for instance engineering background, first introduced the wind ropes principle, for the Liujiaxia bridge wind resistance, according to the vibration frequency characteristics of the different imposed wind cable to determine the45-degree wind the rope for the final imposed programand analysis methods for flutter calculation and analysis under the wind-induced vibration theory(4) Using finite element method for the the Liujiaxia suspension bridge, combined with the relevant provisions of the JTG/T B02-01-2008<Road and Bridge Seismic Design Rules>, the use of wind the rope on the structural seismic analysis of the role of three-dimensional non-uniform excitation. In this paper, two kinds of analytical methods:one is the response spectrum analysis method, and another time history analysis method.Studies show that adding wind the rope on the structure of wind-induced vibration of flutter analysis, results in a wind angle of attack-5°-5°within the flutter critical wind speed values are greater than the Flutter Inspection wind speed value, in line with the wind specificationrequirements. Process using response spectrum analysis method, by contrast, did not join the wind the rope and add a45-degree wind-resistance cable in the displacement, for along the bridge to transverse direction, the vertical bridge to wind the rope on the control structure displacement play a significant role. Aspects of internal forces for the axial force, shear, moment to join the wind ropes pylon structure with different degrees of improvement; in the use of process analysis process using representative schedule wave EI-centro earthquake affected Taft earthquake wave, consider the role of the seismic response of three directions. Displacement by entering the EI-centro earthquake spread to the Taft earthquake wave compared before and after joining the wind cable found in the displacement of large cross in the wind the rope displacement control effect is obviously reflected in the internal force equally, wind the rope on the EI-centro earthquake spread to the Taft earthquake wave to improve the structure internal force is also more obvious.