国内外规范自立式高耸结构等效风荷载及响应比较

Comparative study on equivelent wind loads and dynamic responses of self-standing high-rise structures in different codes

针对GB 50009—2001《建筑结构荷载规范》(2006年版)和GB 50009—2012《建筑结构荷载规范》、美国规范ASME STS-1-2006、欧洲规范BS EN 1993-3-2:2006和CICIND模式规范(Revision 1-1999)等规范关于自立式高耸结构的风振响应计算方法进行了比较研究。对比了各规范中基本风速、风速高度变化系数、湍流强度等基本风特性和结构动力特性的简化计算方法,以及自立式高耸结构顺风向和横风向的风振响应计算方法。选用高度50m和90m的两座自立式钢烟囱作为算例,开展了顺风向和横风向风振响应计算方法的数值模拟对比分析。研究表明:在设计小阻尼、高柔的自立式高耸结构时,顺风向风振响应计算方法相对较为成熟,但气动阻尼的影响不可忽略;对于横风向风振响应,我国规范和欧洲规范(方法1)得到的结果相对偏小,同时,所有方法所得结果与实际观测均有一定的差距,设计时应谨慎选择横风向风振响应计算方法。

A comparative study of the guidelines and procedures about computing wind responses of self-standing high- rise structures in Chinese code （ GB 50009--2001 （ 2006 version） ） , Chinese code （ GB 50009--2012 ） , USA code （ASME STS-1-2006）, Euro code（BS EN 1993-3-2：2006） and CICIND mode code（Revision 1-1999） was carried out. Both basic wind characteristics such as basic wind velocity, wind profile, wind turbulence intensity, etc. and structural dynamic characteristics were summarized and compared. Then, the differences of the calculation methods of equivalent wind loads in these codes were studied, and a detailed example including two self-standing high-rise steel chimneys with the height of 50 m and 90 m were presented to illustrate the overall comparison, in which the equivalent wind loads and their responses were discussed. The results show that as self-standing high-rise structures are characterized by low damping, the aerodynamic damping should not be ignored when computing the along wind vibration. And when using the cross wind vibration computing methods, the responses obtained by the procedures in Chinese code and Euro code （ method 1 ） are smaller than those by the procedures in the other codes. Also, all the cross wind responses of steel chimney 2 calculated by these code methods are smaller than the observed response. Thus the calculation methods should be selected carefully when designing the self-standing high-rise structures.