平面尺寸对矩形高层建筑极值风压影响的研究

Effects of plan dimensions on peak wind pressures of rectangular high-rise buildings

为探索平面尺寸对矩形截面高层建筑表面极值风压分布的影响,对长宽比为1~9的建筑进行了风洞测压试验及后续的脉动风压极值分析,研究了正交风向下不同长宽比建筑各表面极值风压的分布特点,并与我国荷载规范的计算值进行了比较,探讨了全风向角下极值风压包络值在各表面的分布状况及随平面尺寸的变化规律。结果表明,平面尺寸对背风面和侧风面影响较显著,总体而言较小长宽比对极值负压更为不利;我国荷载规范对侧风面和背风面围护结构的风压取值存在诸多偏于不安全的情况。考虑全风向最不利状况的极值风压包络值在墙面分布及随不同平面尺寸变化上均呈现更简单的规律,直接基于包络值分布提出的矩形建筑围护结构风压的取值方法,具有既简便又能更好反映实际风压分布及随平面尺寸变化的-特点。

In order to study effects of plan dimensions on peak wind pressure distribution on rectangular high-rise buildings,wind tunnel pressure tests were conducted for buildings with length-to-width ratios of 1-9,and then extreme value analyses were performed for fluctuating wind pressures.Peak wind pressure distribution features on various surfaces of buildings with different length-to-width ratios under winds with orthogonal directions were investigated and compared with calculated values obtained using the China load code to explore distribution states of peak wind pressure envelope on various surfaces of buildings under all wind direction angles and their varying laws with variation of plan dimensions.Results showed that plan dimensions have significant influences on leeward and side surfaces;overall,smaller length-to-width ratios go against peak negative pressure;values of wind pressure obtained using the China load code for buildings with leeward and side surfaces enclosing have a lot of insecurity;peak wind pressure envelope distribution on wall surface considering the worst case under all wind directions and its change with variation of plan dimensions both reveal simpler laws;the proposed wind pressure value method based on envelope distribution for rectangular buildings with enclosing structure is not only simpler and easier,but also can better reflect actual wind pressure distribution and its features with variation of plan dimensions.