低矮房屋风荷载实测(Ⅰ)——登陆台风近地边界层风特性

第45卷第2期2012年2月

土木工程学报

CHINA CIVIL ENGINEERING JOURNAL

Vol．45Feb．No．22012

基金项目:国家“985”工程“现代结构与桥梁科技创新平台”，国家自然

科学基金重大研究计划(90815030)和“十一五”国家科技支撑计划(2006BAJ06B05-5)作者简介:胡尚瑜，博士研究生收稿日期:2010-

07-30低矮房屋风荷载实测研究(Ⅰ)———登陆台风近地边界层风特性

胡尚瑜

1

李秋胜

1，2

(1．湖南大学建筑安全与节能教育部重点实验室，湖南长沙410082;2．香港城市大学，香港九龙)

摘要:基于可移动双坡屋面实验房及测风塔获取的“苏迪罗”、“彩虹”、“凯萨娜”和“芭玛”等台风登陆期间的三维脉动风速数据，对近地边界层平均风特性和湍流特性进行分析。分析结果表明:近地100m 范围内平均风速剖面符合对数律和指数律分布，平均湍流度剖面符合指数律分布;与良态季风条件下相比，摩擦速度、地面粗糙度长度、平均风速剖面指数α值相对变大，平均湍流度相对增大20%以上;湍流度与阵风因子相关性与Ishizaki 实测结果一致;纵向、横向和竖向三湍流分量的竖向相干函数衰减指数为16．82、7．23、3．69;离地3．2m 高度处各向湍流分量的功率谱值大于10m 高度功率谱值2倍以上，在低频范围各向湍流分量含能量相对要大，湍流功率谱高频段下降相对较快，

在惯性子区各湍流分量的功率谱的分布显著偏离“Kolmogrove-5/3”律。关键词:风荷载;台风观测;边界层;风特性;低矮房屋

中图分类号:TU312+

．1

文献标识码:A 文章编号:1000-

131X (2012)02-0077-08Field measurements of wind loads on a low-rise building —

Part Ⅰ:Near-surface boundary layer wind characteristics of landfall typhoons

Hu Shangyu 1

Li Qiusheng 1，

2

(1．Key Laboratory of Building Safety and Energy Efficiency of the Ministry of Education ，Hunan University ，Changsha 410082，China ;

2．City University of Hong Kong ，Kowloon ，Hong Kong ，China )

Abstract :This paper investigates the mean wind speed and wind turbulence characteristics of typhoons in boundary surface layer based on monitored three-dimensional high resolution wind data during landfall of typhoons “Soudelor ”，

“mujigae ”，“ketsana ”and “parma ”．The analysis results revealed that in the near-surface range (＜100m )vertical distribution of mean wind speed on seashore can be well described by a logarithmic law and power law．The variation of the mean longitudinal turbulence intensity with height approximately follows a power law．Comparing with those obtained under monsoon wind climates ，there are apparent increases in shear stress velocity ，surface roughness length and the exponent of power-law profile．The average values of turbulence intensity observed during the typhoons are more than

20%higher than those obtained during the monsoons．The relation between turbulence intensity and gust factor is proposed ，which is in favorable agreement with that obtained by Ishizaki．The mean decay coefficients in the root coherence functions of the longitudinal ，lateral and vertical wind components are 16．82，7．23and 3．69，respectively．Estimates of the normalized power spectra at 3．2m height are two times larger than those at 10m height for the three wind components．The observed normalized power spectra of longitudinal ，lateral and vertical wind components during the typhoons have significant more energy at lower frequencies and fall faster at high frequencies than the spectra descried by Kolmogrove theory for non-typhoon winds．The slope rates of turbulence spectra of the longitudinal ，lateral and vertical

wind components do not satisfy the-5/3law in the inertial range．

Keywords :wind loads ;typhoon observation ;boundary layer ;wind characteristics ;low-rise building

E-mail :hushangyu@hnu．edu．cn

引

言

近年来国内外学者

［1-3］

从不同的角度对登陆台风

或热带风暴边界层风场和湍流结构进行了观测和研

究，然而从结构设计角度对近地台风湍流特性仍缺乏了解。本文作者及合作者通过研制的可移动平屋顶