基于城市中心区实测风场的高层建筑风荷载特性  

CHARACTERISTICS OF WIND LOADS ACTING ON TALL BUILDINGS BASED ON THE MEASURED WIND FIELD IN URBAN CENTER

作　　者：韩振 李波[1,2] 甄伟 田玉基[1,2] 李晨[1] HAN Zhen;LI Bo;ZHEN Wei;TIAN Yu-ji;LI Chen(School of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China;Beijing’s Key Laboratory of Structural Wind Engineering and Urban Wind Environment,Beijing 100044,China;Beijing Institute of Architectural Design Co.,Ltd.,Beijing 100045,China)

机构地区：[1]北京交通大学土木建筑工程学院,北京100044 [2]结构风工程与城市风环境北京市重点实验室,北京100044 [3]北京市建筑设计研究院有限公司,北京100045

出　　处：《工程力学》2024年第3期124-134,共11页Engineering Mechanics

基　　金：国家自然科学基金项目(51878041);高等学校学科创新引智计划项目(B13002)。

摘　　要：风剖面是影响高层建筑风荷载特性的主要因素。为了探究城市中心区风场下高层建筑的风荷载特性,选取了北京气象塔2013年−2017年连续观测的实测风速数据,采用指数率模型并结合城市边界层分层结构对实测风场风剖面进行了拟合。通过刚性模型风洞测压试验得到了宽厚比D/B=1,2,4三种超高层建筑在实测风场下的风荷载,并将试验结果同规范中的B、D类风场进行了对比。研究表明:基于分层结构,采用指数率模型拟合得到的实测风场幂指数为0.35,其平均风速剖面同D类风场相似,湍流度剖面则大于D类风场;与B、D类风场下的风荷载相比,实测风场对超高层建筑的平均风荷载影响较小,对脉动风荷载的影响较大,且建筑宽厚比增大后,其在实测风场下的脉动风效应显著增强;建筑基底横风向和扭转向力矩系数间具有较强的相关性,且存在极值相关性,特别是90°风向角时的D/B=4建筑,两种相关性在实测风场下均显著增强。The wind profile is a main factor affecting wind load characteristics of tall buildings.To investigate characteristics of wind loads acting on tall buildings in urban central wind field,the measured wind speed data observed continuously from the Beijing Meteorological Tower during 2013-2017 was selected and the power-law was used to fit the measured wind profile based on the layered structure of the urban boundary layer.Wind loads of super-tall buildings with side ratios D/B=1,2 and 4 in the measured wind field were obtained by carrying out a pressure test of rigid models in a wind tunnel and the results were compared with B and D wind fields in the code.The researches show that based on the layered structure,the power exponent of the measured wind field fitted by the power-law is 0.35.The mean wind velocity profile is similar to the D wind field,while the turbulence profile is larger than that of the D wind field.Compared with the wind load in B and D wind fields,the measured wind field has less effect on the mean wind load of super-tall buildings but a greater effect on the fluctuating wind load.Moreover,with the increase of the building side ratio,the fluctuating wind effect is enhanced significantly under the measured wind field.There is a strong correlation between the across-wind and torsional moment coefficients at the base,and correlation in the extreme values exists,especially for the building with D/B=4 at 90°wind direction,while two kinds of correlations are both enhanced in the measured wind field.

关 键 词：超高层建筑 实测风场 风洞试验 风压系数 层风力系数 基底力矩系数 

分 类 号：TU973.213[建筑科学—结构工程]