《结构防灾技术》课程教学课件（讲稿）第三篇 结构抗风 Wind-resistant structure 第八章 大气边界层的平均风特性 characteristics of mean wind in the atmospheric boundary layer

第三篇结构抗风Part 3 Wind-resistant structure第八章大气边界层的平均风特性Chapter 8 characteristics of mean wind in the atmospheric boundarylayer第九章平均风的概率计算Chapter9Probabilisticcalculationofmeanwind第十章脉动风的概率特性Chapter 10Probabilistic characteristics of fluctuating wind第11章结构顺风向随机风振响应Chapter11Structural downwinddynamicresponse第十二章风振控制Chapter 12 Wind vibration control

第三篇 结构抗风 Part 3 Wind-resistant structure 第八章 大气边界层的平均风特性 Chapter 8 characteristics of mean wind in the atmospheric boundary layer 第九章 平均风的概率计算 Chapter 9 Probabilistic calculation of mean wind 第十章 脉动风的概率特性 Chapter 10 Probabilistic characteristics of fluctuating wind 第11章 结构顺风向随机风振响应 Chapter 11 Structural downwind dynamic response 第十二章 风振控制 Chapter 12 Wind vibration control

Introduction一、风的概念Conceptofwind空气从气压大的地方向气压小的地方流动而形成风，风是空气的水平运动Wind is caused by the movement of air from the higher to thelower pressure areas.Wind is thehorizontal movementofair.赤道和低纬度地区：受热量较多，气温高，空气密度小、气压小，且大气因加热膨胀，由地表向高空上升Atequatorandlowlatitudes:moreheatandhighertemperaturecausetheatmosphereexpanding,lowerdensityandpressurerisingfromthesurfaceintosky极地和高纬度地区：受热量较少，气温低，空气密度大、气压大，且大气因冷却收缩由高空向地表下降+Arcticandhighlatitudes:Lessheatandlowertemperaturecausetheatmosphere shrinking,higherdensityandpressuredropping to the surface from sky

一、风的概念 Concept of wind 空气从气压大的地方向气压小的地方流动而形成风，风是空气的水平 运动 Wind is caused by the movement of air from the higher to the lower pressure areas. Wind is the horizontal movement of air. Introduction  赤道和低纬度地区：受热量较多，气温高，空气密度小、气压小,且大 气因加热膨胀，由地表向高空上升  At equator and low latitudes: more heat and higher temperature cause the atmosphere expanding, lower density and pressure, rising from the surface into sky  极地和高纬度地区：受热量较少，气温低，空气密度大、气压大，且 大气因冷却收缩由高空向地表下降  Arctic and high latitudes: Less heat and lower temperature cause the atmosphere shrinking, higher density and pressure, dropping to the surface from sky

Introduction风的两个基本要素：风向和风速，由风向标和风速仪测量Twobasicelementsdescribedwind:directionandspeedmeasuredbyVaneandanemometer北风（8-12级）西北东北风（6级）西东风（7级）东南西南Wind Cup南原理：利用风杯在风作用下的旋转速度来测量风速Principle:Measuringwind speedbytherotational speed ofthewindcupunderwind

风的两个基本要素：风向和风速，由风向标和风速仪测量 Two basic elements described wind: direction and speed, measured by Vane and anemometer Introduction Wind Cup 原理：利用风杯在风作用下的旋转速度来测量风速。 Principle: Measuring wind speed by the rotational speed of the wind cup under wind

风速常用风级表示风速WindSpeedWind speed is usually described byBeaufort windforce scale风级浪高（米）名称风速(米/秒)陆地物象海面波浪WaveBeaufortDescriptionLand conditionsSpeed(m/s)Sea conditionsheight(m)number烟直上平静无风00.00.0-0.2Smoke risesCalmmildvertically.微波峰无飞沫烟示风向Rippleswiththe软风Smoke drift10.10.3-1.5appearanceofscalesindicates windLight airare formed,butdirectionwithoutfoamcrests轻风感觉有风小波峰未破碎21.6-3.30.2LightWind felt onSmall wavelets.breezeexposed skincrestsdonot break小波峰顶破裂微风旗展开Large wavelets.30.6Gentle3.4-5.4lightflagsCrests begin tobreezeextendedbreak

风速常用风级表示 Wind speed is usually described by Beaufort wind force scale 风级 Beaufort number 名称 Description 风速(米/秒) Speed(m/s) 陆地物象 Land conditions 海面波浪 Sea conditions 浪高（米） Wave height(m) 0 无风 Calm 0.0-0.2 烟直上 Smoke rises vertically. 平静 mild 0.0 1 软风 Light air 0.3-1.5 烟示风向 Smoke drift indicates wind direction 微波峰无飞沫 Ripples with the appearance of scales are formed, but without foam crests 0.1 2 轻风 Light breeze 1.6-3.3 感觉有风 Wind felt on exposed skin 小波峰未破碎 Small wavelets. crests do not break 0.2 3 微风 Gentle breeze 3.4-5.4 旌旗展开 light flags extended 小波峰顶破裂 Large wavelets. Crests begin to break 0.6

风速WindSpeed风级名称浪高（米）陆地物象海面波浪风速（米）*DescriptiWaveBeaufortSpeed(m)Land conditionsSea conditionsheight(m)onnumber小浪白沫波峰和风吹起尘土Small waveswith1.04Moderat5.5-7.9Dustandloosebreaking crests.e breezeFairly frequentpaper raisedwhitecaps小树摇摆中浪折沫峰群劲风Small trees inModerate waves of52.0Fresh8.0-10.7leaf begin tosomelength.Manybreezewhitecaps.sway大浪到个飞沫电线有声强风Long waves beginWhistling heard63.010.8-13.8Strongto form.Whitein overheadfoam crests arebreezewiresvery frequent

风级 Beaufort number 名称 Descripti on 风速（米）* Speed(m) 陆地物象 Land conditions 海面波浪 Sea conditions 浪高（米） Wave height(m) 4 和风 Moderat e breeze 5.5-7.9 吹起尘土 Dust and loose paper raised. 小浪白沫波峰 Small waves with breaking crests. Fairly frequent whitecaps. 1.0 5 劲风 Fresh breeze 8.0-10.7 小树摇摆 Small trees in leaf begin to sway 中浪折沫峰群 Moderate waves of some length. Many whitecaps. 2.0 6 强风 Strong breeze 10.8-13.8 电线有声 Whistling heard in overhead wires 大浪到个飞沫 Long waves begin to form. White foam crests are very frequent. 3.0

风速WindSpeed风级陆地物象浪高（米）风速（米）*名称海面波浪LandWaveSpeed(m)BeaufortDescriptionSea conditionss)conditionsheight(m)number疾风步行困难破峰白沫成条High wind,Progress onModerately high7footiswaves with4.013.9-17.1moderategale,seriouslybreaking crestsneargaleimpededforming spindrift浪长高有浪花大风折毁树枝Highwaveswhose85.5Gale,17.2-20.7Somebranchescrestssometimesfresh galebreak off treesroll over浪峰倒卷小损房屋烈风Very high waves97.020.8-24.4structuralSevere galewith overhangingdamage likelycrests

风级 Beaufort number 名称 Description 风速(米)* Speed(m/ s) 陆地物象 Land conditions 海面波浪 Sea conditions 浪高（米） Wave height(m) 7 疾风 High wind, moderate gale, near gale 13.9-17.1 步行困难 Progress on foot is seriously impeded 破峰白沫成条 Moderately high waves with breaking crests forming spindrift 4.0 8 大风 Gale, fresh gale 17.2-20.7 折毁树枝 Some branches break off trees 浪长高有浪花 High waves whose crests sometimes roll over 5.5 9 烈风 Severe gale 20.8-24.4 小损房屋 structural damage likely 浪峰倒卷 Very high waves with overhanging crests 7.0

风速WindSpeed风级名称风速（米）浪高（米）陆地物象海面波浪+DescriptioWaveBeaufortLand conditionsSea conditionsSpeed(m)height(m)nnumber海浪翻滚咆哮拔起树木Considerable109.0狂风storm24.5-28.4Treesare brokentumbling ofwavesoff or uprootedwithheavyimpact损毁普遍波峰全呈飞沫暴风Violent1128.5-32.611.5WidespreadVery large patchesstormoffoamvegetation摧毁巨大Severe飓风widespread海浪溜天hurrican1232.7-14.0damage toHuge wavesevegetation andstructures

风级 Beaufort number 名称 Descriptio n 风速（米） * Speed(m) 陆地物象 Land conditions 海面波浪 Sea conditions 浪高（米） Wave height(m) 10 狂风storm 24.5-28.4 拔起树木 Trees are broken off or uprooted 海浪翻滚咆哮 Considerable tumbling of waves with heavy impact 9.0 11 暴风Violent storm 28.5-32.6 损毁普遍 Widespread vegetation 波峰全呈飞沫 Very large patches of foam 11.5 12 飓风 hurrican e 32.7- 摧毁巨大 Severe widespread damage to vegetation and structures 海浪滔天 Huge waves 14.0

飓风hurricane台风typhoon

飓风 hurricane 台风 typhoon

绪论 Introduction二、风的分类Typesofwind1、热带气旋Tropical cyclone

1、热带气旋 Tropical cyclone 绪 论 Introduction 二、风的分类 Types of wind

热带气旋按中心附近地面最大风速划分为四个等级名称属性台风最大风速出现>32.6米/秒，也即12级以上（64海里/小时或以上)( Typhoon )强热带风暴最大风速出现24.5-32.6米/秒，也即风力10-11级（48-63海里/小时）(Severe tropical storm)热带风暴最大风速出现172-244米/秒，也即风力8-9级（34-47海里/小时）(Tropical storm)热带低压最大风速出现<172米/秒,也即风力为6-7级（22-33海里/小时）(Tropical depression)

热带气旋按中心附近地面最大风速划分为四个等级 名称 属性 台风 （Typhoon） 最大风速出现＞32．6 米/秒，也即 12 级以上（64 海 里/小时或以上） 强热带风暴 (Severe tropical storm) 最大风速出现 24．5-32．6 米/秒，也即风力 10-11 级 （48-63 海里/小时） 热带风暴 (Tropical storm) 最大风速出现17．2-24．4米/秒，也即风力8-9级（34-47 海里/小时） 热带低压 (Tropical depression) 最大风速出现＜17．2 米/秒，也即风力为 6-7 级（22-33 海里/小时）