台风下斜拉桥风致振动和动力特性分析

Analysis of Windinduced Response and Dynamic Properties of Cablestayed Bridge Under Typhoon

摘要:

基于东海大桥健康监测系统得到的斜拉桥在“罗莎”台风下的结构动力响应和环境因素的监测数据,分析了台风的风特征、风致结构振动和风荷载下的结构模态参数的变化.结果表明:随着风速的增加,风的紊流强度是逐渐降低的;随着风速的增大,结构的竖向、横向和扭转加速度是逐渐增大的.基于小波变换和奇异值分解得到在台风期间的结构模态参数,同时对比分析了台风下的结构的模态参数和低风速下的结构的模态参数.在台风作用下,结构的模态频率随着风速的增加而降低,模态阻尼比随着风速的增加变化不明显.

Abstract:

Based on structural health monitoring system of Donghai Bridge,the cablestayed bridge response and environmental factors were measured during the typhoon Krosa.The characteristics of typhoon,windinduced response and structural modal parameters variation were analyzed.The results demonstrate that the turbulence intensity is increasing with the wind speed. The wind induced response also increases when the wind speed increases.The structural modal parameters during typhoon were identified by the method of wavelet transform and singular value decomposition,and the modal parameters during the typhoon also were compared with that under the condition of low wind speed.Influenced by typhoon,structural modal frequencies were decreased and the modal damping ratios were not changed significantly when the wind speed increased.