基于风洞试验的对称截面高层建筑三维等效静力风荷载研究

Analysis of three dimensional equivalent static wind loads on symmetrical high-rise buildings based on wind tunnel tests

基于刚性模型表面测压风洞试验建立高层建筑三维风荷载模型,进而运用振型加速度法求解风振响应动力方程,得到了包含拟静力项和惯性力项的弹性力响应解,并推导了对称截面高层建筑顺风向、横风向和扭转向风致随机内力响应。在此基础上提出了基于内力响应等效的可考虑高阶振型贡献的对称截面高层建筑顺风向、横风向和扭转向等效静力风荷载计算方法。结合某一对称截面高层建筑工程实例,对采用上述方法计算得到的结构三维等效静力风荷载进行分析并与我国规范方法顺风向等效静力风荷载计算结果进行比较。结果表明,高层建筑结构抗风设计应该考虑三维等效静力风荷载,且二阶振型对高层建筑等效静力风荷载的贡献不可忽视。

Based on synchronous surface pressure scanning of rigid model in wind tunnel test, three dimensional wind load models of high-rise buildings were obtained. Furthermore, the random internal force responses of buildings in along-wind, across-wind and torsional directions were obtained by applying modal acceleration method, which express the restoring force solution in terms of quasi-static force item and inertia force item. Accordingly the calculation methods of equivalent static wind loads, in which the contributions of the higher mode can be considered, of symmetrical high-rise buildings in along-wind, across-wind and torsional directions were deduced based on internal forces equivalence. Finally by analyzing the three dimensional equivalent static wind loads of an actual symmetrical high-rise buildings obtained by this method, and comparing with the along-wind equivalent static wind loads obtained by the national load code, it is indicated that three dimensional equivalent static wind loads should be considered for the wind resistant design of high-rise buildings, and that the contributions of the second mode to the equivalent static wind loads of high-rise buildings cannot be neglected.