钢结构基本温度及风温荷载组合系数研究

Study on basic temperature and combined coefficient of wind and temperature loads for steel structure

现行《建筑结构荷载规范》(GB 50009—2012)(简称荷载规范)的基本气温主要针对热传导性能较差的混凝土,根据月平均极值温度确定,但是对于热传导较好的钢结构,基本温度应根据年极值温度统计确定。以全国631个气象台1951年以来的年极值气温为样本,假定服从极值I型分布,统计确定了各地区的基本温度。与荷载规范进行了对比,建议对于钢结构进行荷载取值时将现行荷载规范相应地区基本气温提高到1.36倍使用。荷载规范中的风温组合系数是基于经验确定的,未考虑荷载间的相互影响。根据全国主要地区风速和温度的历史数据,分析不同跨度、矢高和刚度的单层网壳结构的风温组合系数。结果表明风、温度的组合系数均需一定程度的提高,以保证结构服役期安全,给荷载规范的修订提供参考。

The basic temperature of the existing Load code for the design of building structures（ GB 50009—2012）（ referred to as the load specification） is mainly for concrete with poor heat conduction performance,which is determined according to the monthly mean extreme temperature,but the basic temperature for the steel structure with better heat conduction should be determined by annual extreme temperature statistics.Taking the annual extreme temperature of 631 meteorological stations since 1951 as the sample,it was assumed to follow extreme temperature type I distribution,and the basic temperature of each region was determined statistically.Compared with the load specification,it was recommended that the temperature value of the steel structure should be increased to 1.36 times of the basic temperature value in corresponding region in load specification.The combined coefficient of wind and temperature loads in the load specification is determined based on experience and does not take into account the interaction between loads.Based on the historical data of wind speed and temperature in the main areas of China,combined coefficient of wind and temperature loads of single-layer reticulated shell with different spans,vector heights and stiffness were analyzed.The results show that the combined coefficient of wind and temperature loads needs to be improved to a certain extent to ensure the safety of the structure in service life,which provides reference for the revision of the load specification.