国内外建筑围护结构风荷载规范对比研究

Comparative study on wind loads of building cladding and components among domestic and international standards

针对围护结构设计风荷载,分析了如下风荷载规范中的相关规定:中国GB 50009—2012、中国JGJ/T 481—2019、美国ASCE/SEI 7⁃16、日本AIJ⁃2015、澳大利亚/新西兰AS/NZS 1170.2:2021、欧洲BS EN 1991⁃1⁃4:2005、加拿大NBCC 2015。分析结果表明,国内外围护结构风荷载规范的理论基础主要包括准定常理论和风压极值理论,均将设计风荷载表示成设计风速与设计风压系数的乘积;设计风速的确定需要考虑地貌、局部地形、季节、风向、相邻建筑干扰等因素的影响,各国规范对这些因素考虑的详尽程度不一;设计风压系数则需要考虑来流湍流和特征湍流共同作用下风压的时间随机性和空间分布不均匀性、不同方向来流时建筑表面风压的差异性、建筑表面风压相关性等因素,各国规范均通过风压分区和面积折减较好地考虑了这些因素,不同之处在于不同规范所涵盖的建筑体型、考虑建筑几何参数影响的风压分区结果及面积折减的特征有所区别。

Aiming at the design wind load of cladding and components,the relevant provisions in the following wind load codes were analyzed:China GB 50009—2012,China JGJ/T 481—2019,USA ASCE/SEI 7⁃16,Japan AIJ⁃2015,Australia/New Zealand AS/NZS 1170.2:2021,Europe BS EN 1991⁃1⁃4:2005,Canada NBCC 2015.The analysis results show that the theoretical basis of the wind load for cladding and components among domestic and international standards mainly includes quasi⁃steady theory and extreme wind pressure theory,and the design wind load is expressed as the product of design wind speed and design wind pressure coefficient.Determining the design wind speed requires consideration of factors such as landform,local topography,season,wind direction and interference from adjacent buildings.The specifications from codes of various countries offer different levels of detail in considering these factors.The design wind pressure coefficient needs to consider the randomness of time and the inhomogeneity of space caused by incoming flow turbulence and signature turbulence,the difference of wind pressure on the building surface in different directions,and the correlation of wind pressure on the building surface.These factors are well considered by wind pressure zoning and area reduction in codes of various countries.The differences exist in the architectural forms covered by various standards,the inclusion of building geometric parameters in wind pressure zoning results,and the characteristics of area reduction in distinct zones.