超高层建筑风致振动的P-Δ效应

P-Δ Effects on Wind-induced Response of Super-tall Buildings

基于超高层建筑的质点系简化模型,构造等效水平力偶代替重力引起的附加倾覆弯矩,并将该水平力偶项转化为一个附加刚度矩阵,只需要将原有刚度矩阵减去该附加刚度矩阵,即可实现常规风振响应分析方法框架下的考虑P-Δ效应的结构风振响应分析。将上述方法应用于432m高的广州西塔风振响应分析中,结果表明:考虑P-Δ效应后,在敏感风向角下的顶部峰值位移、峰值加速度和基底倾覆弯矩均比不考虑P-Δ效应时有显著增大,说明超高层建筑风致振动的P-Δ效应应该得到足够的重视。

Based on a simplified tall building model,the additional overturning moment generated by gravity is replaced by a pair of horizontal forces,and then,these additional forces are transformed into the product of an additional stiffness matrix and the displacement vector. Hence,by subtracting the additional stiffness matrix of the structure,the wind induced vibration of a super-tall building considering P-Δ effects can be achieved on the basis of the conventional vibration analysis framework. The proposed method is utilized to analyze the wind-induced response of the Guangzhou West Tower（ a tall building with 432 m height） and to observe the P-Δ effects on it. It is concluded that,when the P-Δ effects are considered,the peak displacement,acceleration atop the building and the overturning moment on the base are obviously larger than those do not consider the P-Δ effects. Therefore,P-Δeffects on wind-induced responses of tall buildings should be paid more attention.