不同深宽比矩形平面超高层建筑顺风向风致荷载的试验研究  

Experimental Study on Downwind-induced Loads of Rectangular Plane Super High-rise Buildings with Different Aspect Ratios

作　　者：陈伟兴 王奕可 CHEN Weixing;WANG Yike(State Key Laboratory of Subtropical Building Science,South China University of Technology,Guangzhou 510641,China)

机构地区：[1]华南理工大学亚热带建筑科学国家重点实验室,广东广州510641

出　　处：《甘肃科学学报》2022年第5期86-93,共8页Journal of Gansu Sciences

基　　金：国家自然科学基金项目(52078221)。

摘　　要：超高层建筑正朝着更高、更柔的方向发展。结构设计中常常发现较小深宽比的板式超高层建筑起控制性作用的仍是顺风向风荷载(DWL)。针对高度为200 m左右的矩形平面超高层建筑,采用高频底座测力天平技术,在B、C两类风场中对7种深宽比和3种凹角率的超高层建筑的顺风向风致荷载特性进行了风洞试验研究,重点考察了整体体型系数的分布规律,并分析了深宽比、湍流度、凹角率和阻尼比对DWL的影响。结果表明:《建筑结构荷载规范》在一定的深宽比范围内低估了结构的整体体型系数;宽边迎风时的顺风向平均风荷载(DMWL)最大约为窄边迎风时的6.61倍,其对D/B的敏感度显著大于顺风向脉动风荷载(DFWL),且DMWL在较小深宽比时起控制作用;B类地貌下的DMWL最大高出C类地貌66.7%;D/B=3和D/B=4的最优凹角率分别为10%和15%,分别能降低23.76%和19.57%的DMWL;采用2%阻尼比计算得到的最大DFWL比5%阻尼比的计算结果高出35.37%。Super high-rise buildings are developing in a higher and softer direction.In structural design, it is often found that the controlling role of slab-type super high-rise buildings with small aspect ratio is still downwind wind load(DWL).Aiming at the rectangular plane super high-rise building with a height of about 200 m, the high frequency base force balance technology is used to study the downwind load characteristics of the super high-rise building with 7 kinds of aspect ratio and 3 kinds of concave angle ratio in B and C wind fields.The distribution law of the overall shape coefficient is investigated emphatically, and the effects of aspect ratio, turbulence, concave angle ratio and damping ratio on DWL are analyzed.The results show that Building Structure Load Code underestimates the overall shape coefficient of the structure within a certain aspect ratio.The maximum downwind mean wind load(DMWL) of the wide side upwind is about 6.61 times that of the narrow side upwind, and its sensitivity to D/B is significantly higher than that of the downwind fluctuating wind load(DFWL),and DMWL controls when the aspect ratio is small.The maximum DMWL of class B landforms is 66.7% higher than that of class C landforms.The optimal concave angle ratio of D/B=3 and D/B=4 is 10% and 15% respectively, which can reduce the DMWL by 23.76% and 19.57%,respectively.The DFWL calculated by using the 2% damping ratio is up to 35.37% higher than the calculation result of the 5% damping ratio.

关 键 词：板式超高层建筑 顺风向风致荷载 整体体型系数 深宽比 风洞试验 

分 类 号：TU312.1[建筑科学—结构工程]