Research On Vortex-induced Resonance Of The Main Beam

Vortex-induced resonance problem in bridge structure is one of the main problems in wind-resistent design of long span bridge, especially for the large span steel box girder cable-stayed bridge, steel box girder suspension bridge and steel structure continuous beam bridge, which are builted massively currently in domestic, and their deck cross section's vortex-induced resonance problem has been the focus of wind-resistent studies.This paper takes Gangzhu'ao Bridge and Xiazhang Bridge as engineering examples, studies the vortex-induced resonance characters of separate and integral steel box girder cable-stayed bridge, and analyzes the test results. Estimating the wind speed of vortex, vertical bending displacement and torsion angle of the two bridges with the method provided by "Wind-resistent Design Specification for Highway Bridges", then comparing them with the text results, and verifying the reliability of the estimate method. With the known vortex-induced resonance related experiment parameters, calculating vertical bending vibration amplitude and verifying the influence of related parameters on vortex-induced vibration by using Scanlan experience linear model theory.In addition, this paper also conducts the comparative analysis about three deck cross section's vortex-excited resonance of nizhou waterway bridge, through compared dynamic behaviour, test parameters and experimental results. Analyze the influence on the bridge's vertical bending vortex-excited resonance and torsional vortex-induced resonance, which is caused by vertical bending fundamental frequency, torsional fundamental frequency, equivalent mass, moments of equivalent mass of inertia, aerodynamic configuration.