Design of Buildings for Wind: A Guide for ASCE 7-10 Standard Users and Designers of Special Structures (Hardcover, 2)

PREFACE xi

PART I INTRODUCTION 1

1 OVERVIEW 3

PART II GUIDE TO THE ASCE 7-10 STANDARD PROVISIONS ON WIND LOADS 7

2 ASCE 7-10 WIND LOADING PROVISIONS 9

2.1 Introduction / 9

2.2 ASCE 7-10 Standard: An Overview / 10

2.3 Organization of the Guide: Chapters 3 to 9 / 19

3 REGULAR AND SIMPLIFIED APPROACH: RISK CATEGORY, BASIC WIND SPEED, ENCLOSURE, EXPOSURE, TOPOGRAPHIC FACTOR 21

3.1 Risk Category (ASCE Table 1.5-1) / 21

3.2 Basic Wind Speed V (ASCE Sect. 26.5, ASCE Figs. 26.5.-1a, b, c) / 22

3.3 Enclosure Classification (ASCE Sects. 26.2 and 26.10) / 23

3.4 Exposure Category (ASCE Sect. 26.7) / 24

3.5 Topographic Factor Kzt (ASCE Sect. 26.8, ASCE Fig. 26.8-1) / 27

4 REGULAR APPROACH: STEPS COMMON TO ALL BUILDINGS/OTHER STRUCTURES (MWFRS AND C&C) 31

4.1 Introduction / 31

4.2 Regular Approach: Steps Common to All Buildings and Other Structures (MWFRS and C&C) / 32

5 REGULAR APPROACH: BUILDINGS, PARAPETS, OVERHANGS (‘‘DIRECTIONAL’’ PROCEDURE), MWFRS 37

5.1 Introduction / 37

5.2 Regular Approach: Enclosed or Partially Enclosed Buildings of All Heights, MWFRS / 37

5.3 Regular Approach: Roof Overhangs and Parapets, MWFRS / 53

5.4 Regular Approach: Open Buildings with Monoslope, Pitched, or Troughed Free Roofs, MWFRS / 55

6 REGULAR APPROACH: LOW-RISE BUILDINGS, PARAPETS, OVERHANGS (‘‘ENVELOPE’’ PROCEDURE), MWFRS 57

6.1 Net Pressures on Walls and Roof / 57

6.2 Comparison Between Results Based on ASCE Sects. 27.4.1 and 28.4.1 / 62

6.3 Regular Approach: Parapets and Roof Overhangs, MWFRS / 63

7 REGULAR APPROACH: STRUCTURES OTHER THAN BUILDINGS, MWFRS 65

7.1 Solid Freestanding Walls and Solid Signs / 65

7.2 Open Signs, Lattice Frameworks, Trussed Towers / 69

7.3 Chimneys, Tanks, Rooftop Equipment, and Similar Structures / 74

7.4 Solid Attached Signs / 75

7.5 Rooftop Structures and Equipment on Buildings / 77

8 SIMPLIFIED APPROACH: ENCLOSED SIMPLE DIAPHRAGM BUILDINGS, PARAPETS, OVERHANGS (MWFRS) 81

8.1 Simplified Approach: Class 1 Buildings, Walls and Roof, MWFRS / 81

8.2 Simplified Approach: Parapets, MWFRS / 85

8.3 Simplified Approach: Roof Overhangs, MWFRS / 85

8.4 Simplified Approach: Class 2 Buildings, Walls and Roof, MWFRS / 86

8.5 Simplified Approach: Simple Diaphragm Low-Rise Buildings, MWFRS / 90

9 REGULAR AND SIMPLIFIED APPROACHES: C&C 95

9.1 Introduction / 95

9.2 Regular Approach / 95

9.3 Simplified Approaches / 105

PART III WIND ENGINEERING FUNDAMENTALS 107

10 ATMOSPHERIC CIRCULATIONS 109

10.1 Atmospheric Hydrodynamics / 109

10.2 Windstorms / 113

11 THE ATMOSPHERIC BOUNDARY LAYER 117

11.1 Wind Speeds and Averaging Times / 118

11.2 Wind Speed Profiles / 121

11.3 Atmospheric Turbulence / 130

12 EXTREME WIND SPEEDS AND WIND-INDUCED EFFECTS 137

12.1 Wind Speed Data / 138

12.2 Cumulative Distributions, Exceedance Probabilities, Mean Recurrence Intervals / 141

12.3 Parametric Estimates of N-Year Wind Speeds; Closed Form Estimators; Software / 143

12.4 Probabilistic Estimates of Wind Effects Based on Nondirectional and Directional Wind Speed Data / 149

12.5 Development of Directional Databases of Hurricane Wind Speeds / 153

12.6 Development of Directional Databases of Non-Hurricane Wind Speeds / 155

12.7 Non-Parametric Statistics, Application to One-Dimensional Time Series / 157

12.8 Error Estimates / 159

13 BLUFF BODY AERODYNAMICS BASICS; AERODYNAMIC TESTING 163

13.1 Introduction / 163

13.2 Bluff Body Aerodynamics / 163

13.3 Aerodynamic Testing / 173

13.4 Low-Frequency Turbulence and Aerodynamic Pressures on Residential Homes / 183

14 STRUCTURAL DYNAMICS 185

14.1 Introduction / 185

14.2 The Single-Degree-of Freedom Linear System / 186

14.3 Continuously Distributed Linear Systems / 190

14.4 Time Domain Solutions for Three-Dimensional Dynamic Response / 199

15 AEROELASTICITY 203

15.1 Introduction / 203

15.2 Vortex-Induced Oscillations / 205

15.3 Galloping / 206

15.4 Flutter / 210

16 STRUCTURAL RELIABILITY UNDER WIND LOADING 217

16.1 Introduction / 217

16.2 First-Order Second-Moment Approach, Load and Resistance Factors / 220

16.3 Dependence of Wind Effects on Wind Directionality / 225

16.4 Structural Strength Reserve / 226

16.5 Design Criteria for Multi-Hazard Regions / 228

16.6 Individual Uncertainties and Overall Uncertainty in the Estimation of Wind Effects / 229

16.7 Calibration of Design MRIs in the Presence of Dynamic Effects or of Large Knowledge Uncertainties / 232

17 LOSS ESTIMATION 237

17.1 Introduction / 237

17.2 Elements of Damage Estimation Procedures / 238

17.3 Loss Estimation / 245

PART IV WIND EFFECTS ON BUILDINGS 247

18 RIGID BUILDINGS 249

18.1 Introduction / 249

18.2 Database-Assisted Design (DAD) / 252

18.3 Wind Directionality Effects / 258

18.4 Uncertainties in the Estimation of Wind Effects / 259

19 TALL BUILDINGS 261

19.1 Introduction / 261

19.2 High-Frequency Force Balance Approach (HFFB) / 263

19.3 Aeroelastic Effects. Testing Based on Strain Measurements / 265

19.4 Database-Assisted Design / 269

19.5 Serviceability Requirements / 278

19.6 Preliminary Estimates of Flexible Building Response / 279

PART V APPENDICES 287

APPENDIXA1 RANDOM PROCESSES 289

A1.1 Fourier Series and Fourier Integrals / 290

A1.2 Parseval’s Equality / 291

A1.3 Spectral Density Function of a Random Stationary Signal / 292

A1.4 Autocorrelation Function of a Random Stationary Signal / 293

A1.5 Cross-Covariance Function, Co-Spectrum, Quadrature Spectrum, Coherence / 295

A1.6 Mean Upcrossing and Outcrossing Rate for a Gaussian Process / 296

A1.7 Probability Distribution of the Peak Value of a Normally Distributed Random Signal / 297

A1.8 Probability Distribution of the Peak Value of a Non-Gaussian Random Signal / 298

APPENDIXA2 MEAN WIND PROFILES AND ATMOSPHERIC BOUNDARY LAYER DEPTH 301

A2.1 Equations of Balance of Momenta within the Atmospheric Boundary Layer / 301

A2.2 The Turbulent Ekman Layer / 302

APPENDIXA3 SPECTRA OF TURBULENT VELOCITY FLUCTUATIONS, KOLMOGOROV HYPOTHESES 307

APPENDIXA4 WIND DIRECTIONALITY EFFECTS, OUTCROSSING AND SECTOR-BY-SECTOR APPROACHES 311

A4.1 Approach Based on the Outcrossing of the Limit-State Boundary / 311

A4.2 The Sector-By-Sector Approach [18-10] / 313

APPENDIXA5 REPORT ON ESTIMATION OF WIND EFFECTS ON THE WORLD TRADE CENTER TOWERS 315

REFERENCES 323

INDEX 333