利通广场台风特性与风致振动分析

Wind field characteristic and wind-induced vibration analysis of litong plaza under typhoon effect

对利通广场实施了在台风"韦森特"影响下的楼顶风速、风向和风致加速度响应的实时同步测试。获取了本次台风影响时此超高层建筑顶部的湍流强度、阵风因子及脉动风速功率谱密度等风场特性。通过对风致加速度的分析,研究了风致加速度的频谱特征、结构自振频率及其振型等相关动力特征,采用随机减量法求得结构第一振型阻尼比与振幅的非线性关系。另一方面,通过对此超高层建筑在无风荷载的环境激励条件下GPS楼顶位移的测试和分析,探讨了GPS多路径效应的形成机制及消除方法。并将GPS位移以及风致加速度获得的结构自振频率,与有限元分析结果进行对比分析,验证了两种测试方法均能有效识别实际结构的自振频率等动力特征。上述实测分析结果可为超高层建筑抗风设计提供参考。

The simultaneous field measurement of wind speed,wind direction and wind-induced acceleration response were conducted on the super tall building of Litong plaza in Guangzhou when typhoon Vicente affected the building.The wind filed characteristics at the top of the building were obtained through statistical analysis.The frequency-spectrum characteristics of wind-induced responses and the dynamic characteristics were identified from the measured wind-induced acceleration data.The nonlinear damping ratio was also obtained by using the random decrement technique. On the other hand the displacements at the top of the building were previously measured by GPS system under ambient condition.The multi-path effect of the measured displacement was investigated and the removing method was studied.The natural frequencies obtained by different methods were compared.The effectiveness of the identified natural frequencies was therefore verified by the compared results.