中央扣对大跨度悬索桥风致抖振响应的影响

摘要

润扬长江公路大桥南汊悬索桥(润扬悬索桥)在国内首次采用将缆、梁固结的刚性中央扣代替已建悬索桥常用的跨中短吊索.基于ANSYS建立该桥的三维有限元计算模型,同时利用桥址区实测强风特性数据、基于谐波合成法和FFT技术建立桥址区考虑桥塔风效应的三维脉动风场,在此基础上进行该桥非线性抖振响应时域分析,重点研究刚性中央扣对大跨度悬索桥风致抖振响应的影响.研究结果表明,中央扣结构对大跨度悬索桥抖振响应的影响与风速有关.相对而言,主梁较主塔的抖振响应受中央扣的影响大;竖向位移较横向和扭转位移受到的影响大.研究结果为该桥的风致抖振性能评价提供必要的研究基础,同时为后刚性中央扣结构在大跨悬索桥中的广泛应用提供参考.%Rigid central buckle is employed, for the first time in China, in the Runyang Suspension Bridge (RSB) to replace the commonly used short suspender in the main span. A finite element model for the RSB is established using the ANSYS software. Combining with the spectral representation method and the fast Fourier transform (FFT) technique, the three-dimensional turbulence wind field with the tower wind effect is simulated, based on the measurement data of strong wind characteristics of the bridge. Nonlinear buffeting response time-domain analysis is conducted and the influence of the central buckle on the wind-induced buffeting response of the long-span suspension bridge is studied. The results show that the influence of the central buckle on the buffeting response of the long-span suspension bridges is related to the wind speed. The buffeting response of the deck is influenced more significantly than that of the two towers. The vertical displacement is influenced more significantly than the transverse and torsional displacements.