Structural Load Determination

Structural Load Determination

TABLE OF CONTENTS

CHAPTER 1 – INTRODUCTION

1.1  OVERVIEW.

1.2  SCOPE......   1-2 

1.3  REFERENCES .........   1-4 

CHAPTER 2 – LOAD COMBINATIONS 

2.1  INTRODUCTION ....   2-1 

2.  LOAD EFFECTS......   2-1 

2.3  LOAD COMBINATIONS USING STRENGTH DESIGN OR LOAD 

AND RESISTANCE FACTOR DESIGN ..... 2-2 

2.4  LOAD COMBINATIONS USING ALLOWABLE STRESS DESIGN . 2-4 

2.5  LOAD COMBINATIONS WITH OVERSTRENGTH FACTOR .....   2-8 

2.6  LOAD COMBINATIONS FOR EXTRAORDINARY EVENTS...... 2-11 

2.7  EXAMPLES ............. 2-11 

  2.7.1  Example 2.1 – Column in Office Building, Strength Design 

Load Combinations for Axial Loads ....   2-12 

  2.7.2  Example 2.2 – Column in Office Building, Strength Design 

Load Combinations for Axial Loads and Bending Moments ....   2-13 

  2.7.3  Example 2.3 – Beam in University Building, Strength Design 

Load Combinations for Shear Forces and Bending Moments...   2-14 

  2.7.4  Example 2.4 – Beam in University Building, Basic Allowable Stress  

    Design Load Combinations for Shear Forces and Bending Moments.......   2-16 

  2.7.5  Example 2.5 – Beam in University Building, Alternative Basic Allowable 

    Stress Design Load Combinations for Shear Forces and Bending Moments ............   2-18 

  2.7.6  Example 2.6 – Collector Beam in Residential Building, Load Combinations using 

    Strength Design and Basic Load Combinations for Strength Design with 

    Overstrength Factor for Axial Forces, Shear Forces, and Bending Moments ...........   2-19 

  2.7.7  Example 2.7 – Collector Beam in Residential Building, Load Combinations using 

    Allowable Stress Design (Basic Load Combinations) and Basic Combinations 

     for Allowable Stress Design with Overstrength Factor for Axial Forces, Shear 

    Forces, and Bending Moments ........   2-21 

2.7.8  Example 2.8 – Collector Beam in Residential Building, Load Combinations using 

    Allowable Stress Design (Alternative Basic Load Combinations) and Basic 

    Combinations for Allowable Stress Design with Overstrength Factor for Axial 

    Forces, Shear Forces, and Bending Moments ......   2-22 

2.7.9  Example 2.9 – Timber Pile in Residential Building, Basic Allowable Stress Design 

    Load Combinations for Axial Forces ...   2-23 

CHAPTER 3 – DEAD, LIVE, AND RAIN LOADS 

3.1  DEAD LOADS......... 3-1 

3.2  LIVE LOADS........... 3-2 

3.2.1  General ....... 3-2 

3.2.2  Reduction in Live Loads . 3-3 

3.2.3  Distribution of Floor Loads.............   3-9 

3.2.4  Roof Loads . 3-10 

3.2.5  Crane Loads 3-11 

3.2.6  Interior Walls and Partitions............ 3-12 

3.3  RAIN LOADS .......... 3-12 

3.4  EXAMPLES ............. 3-13 

3.4.1  Example 3.1 – Live Load Reduction, General Method of IBC 1607.9.1 .. 3-14 

3.4.2  Example 3.2 – Live Load Reduction, Alternate Method of IBC 1607.9.2  3-24 

3.4.3  Example 3.3 – Live Load Reduction on a Girder. 3-32 

3.4.4  Example 3.4 – Rain Load, IBC 1611.... 3-33 

CHAPTER 4 – SNOW LOADS

4.1  INTRODUCTION ....   4-1 

4.2  FLOWCHARTS .......   4-4 

4.3  EXAMPLES ............. 4-14 

4.3.1  Example 4.1 – Warehouse Building, Roof Slope of 1/2 on 12.. 4-14 

4.3.2  Example 4.2 – Warehouse Building, Roof Slope of 1/4 on 12..   4-19 

4.3.3  Example 4.3 – Warehouse Building (Roof Slope of 1/2 on 12) and Adjoining Office Building (Roof Slope of 1/2 on 12) ... 4-20 

4.3.4  Example 4.4 – Six-Story Hotel with Parapet Walls..............   4-28 

4.3.5  Example 4.5 – Six-Story Hotel with Rooftop Unit...............   4-33 

4.3.6  Example 4.6 – Agricultural Building....   4-35 

4.3.7  Example 4.7 – University Facility with Sawtooth Roof.......   4-39 

4.3.8  Example 4.8 – Public Utility Facility with Curved Roof......   4-42 

CHAPTER 5 – WIND LOADS

5.1  INTRODUCTION ....   5-1 

5.2  FLOWCHARTS .......   5-3 

  5.2.1  Allowed Procedures.........   5-5

  5.2.2  Method 1 – Simplified Procedure.... 5-7 

  5.2.3  Method 2 – Analytical Procedure....   5-11 

  5.2.4  Alternate All-heights Method..........   5-30 

5.3  EXAMPLES ............. 5-32 

  5.3.1  Example 5.1 – Warehouse Building using Method 1, Simplified Procedure    

5.3.2  Example 5.2 – Warehouse Building using Low-rise Building Provisions of  Method 2, Analytical Method..........   5-43 

  5.3.3  Example 5.3 – Warehouse Building using Provisions of Method 2, Analytical Procedure......   5-52 

  5.3.4  Example 5.4 – Warehouse Building using Alternate All-heights Method.   5-60 

  5.3.5  Example 5.5 – Residential Building using Method 2, Analytical Procedure............. 5-69 

  5.3.6  Example 5.6 – Six-Story Hotel using Method 2, Analytical Procedure .... 5-87 

  5.3.7  Example 5.7 – Six-Story Hotel Located on an Escarpment using Method 2, Analytical Procedure . 5-98 

  5.3.8  Example 5.8 – Six-Story Hotel using Alternate All-heights Method 

  5.3.9  Example 5.9 – Fifteen-Story Office Building using Method 2,  Analytical Procedure ....... 5-110 

  5.3.10  Example 5.10 – Agricultural Building using Method 2, Analytical Procedure......... 5-125 

5.3.11  Example 5.11 – Freestanding Masonry Wall using Method 2, Analytical Procedure .......   5-131 

CHAPTER 6 – EARTHQUAKE LOADS 

6.1  INTRODUCTION .... 6-1 

6.2  SEISMIC DESIGN CRITERIA.....   6-2 

  6.2.1  Seismic Ground Motion Values ...... 6-2 

  6.2.2  Occupancy Category and Importance Factor ....... 6-4 

  6.2.3  Seismic Design Category  6-5 

  6.2.  Design Requirements for SDC A .... 6-5 

6.3  SEISMIC DESIGN REQUIREMENTS FOR BUILDING STRUCTURES

  6.3.1  Basic Requirements......... 6-6 

  6.3.2  Seismic Force-Resisting Systems.... 6-6 

  6.3.3  Diaphragm Flexibility, Configuration Irregularities, and Redundancy .....   6-7 

  6.3.4  Seismic Load Effects and Combinations.............. 6-12 

  6.3.5  Direction of Loading ....... 6-13 

  6.3.6  Analysis Procedure Selection .......... 6-15 

  6.3.7  Modeling Criteria ............ 6-15 

  6.3.8  Equivalent Lateral Force Procedure    6-15 

  6.3.  Modal Response Spectral Analysis . 6-18 

  6.310  Diaphragms, Chords, and Collectors.... 6-18 

  6.3.11  Structural Walls and Their Anchorage . 6-20 

  6.3.12  Drift and Deformation ..... 6-20 

  6.3.13  Foundation Design .......... 6-20 

  6.3.14  Simplified Alternative Structural Design Criteria for Simple 

Bearing Wall or Building Frame Systems............ 6-21 

6.4  SEISMIC DESIGN REQUIREMENTS FOR NONSTRUCTURAL COMPONENTS.......... 6-22   6.4.1  General ....... 6-22 

  6.4.2  Seismic Demands on Nonstructural Components  6-23 

  6.4.3  Nonstructural Component Anchorage.. 6-23 

  6.4.4  Architectural Components............... 6-23 

  6.4.5  Mechanical and Electrical Components ............... 6-24 

6.5  SEISMIC DESIGN REQUIREMENTS FOR NONBUILDING STRUCTURES ..

  6.5.1  General ....... 6-24 

  6.5.2  Reference Documents...... 6-25 

  6.5.3  Nonbuilding Structures Supported by Other Structures .......   6-25 

  6.5.4  Structural Design Requirements...... 6-25 

  6.5.5  Nonbuilding Structures Similar to Buildings ....... 6-25 

  6.5.6  Nonbuilding Structures Not Similar to Buildings. 6-26 

  6.5.7 Tanks and Vessels ........... 6-26 

6.6  FLOWCHARTS ....... 6-26 

  6.6.1  Seismic Design Criteria... 6-28 

  6.6.2  Seismic Design Requirements for Building Structures ........ 6-38 

  6.6.3  Seismic Design Requirements for Nonstructural Components . 6-55 

  6.6.4  Seismic Design Requirements for Nonbuilding Structures .. 6-57 

6.7  EXAMPLES ............. 6-61 

  6.7.1  Example 6.1 – Residential Building, Seismic Design Category 6-61 

  6.7.2  Example 6.2 – Residential Building, Permitted Analytical Procedure......   6-64 

  6.7.3  Example 6.3 – Office Building, Seismic Design Category ..   6-70 

  6.7.4  Example 6.4 – Office Building, Permitted Analytical Procedure.............. 6-74 

  6.7.5  Example 6.5 – Office Building, Allowable Story Drift........ 6-84 

  6.7.6  Example 6.6 – Office Building, P-delta Effects ... 6-86 

  6.7.7  Example 6.7 – Health Care Facility, Diaphragm Design Forces............... 6-88 

  6.7.8  Example 6.8 – Health Care Facility, Nonstructural Component ...............   6-93 

  6.7.9  Example 6.9 – Residential Building, Vertical Combination  of Structural Systems....... 6-95 

  6.7.10  Example 6.10 – Warehouse Building, Design of Roof 

Diaphragm, Collectors, and Wall Panels.............. 6-102 

  6.7.11  Example 6.11 – Retail Building, Simplified Design Method ....   6-112 

  6.7.12  Example 6.12 – Nonbuilding Structure  6-121

CHAPTER 7 – FLOOD LOADS

7.1  INTRODUCTION ....   7-1 

7.2  FLOOD HAZARD AREAS ..........   7-1 

7.3  DESIGN AND CONSTRUCTION ............... 7-3   7.3.1  General ....... 7-3 

  7..2  Flood Loads 7-4 

74  EXAMPLES ............. 7-10 

  7.4.  Example 7.1 – Residential Building Located in a Non-Coastal A Zone ... 7-10 

  7.4.2  Example 7.2 – Residential Building Located in a Coastal A Zone............   7-14 

  7.4.3  Example 7.3 – Residential Building Located in a V Zone ... 7-18 

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High Performance Concrete

High Performance Concrete

Contents

1 Terminology: some personal choices 

1.1 About the title of this book 1

1.2 Water/cement, water/cementitious materials or water/binder ratio 2

1.3 Normal strength concrete/ordinary concrete/usual concrete 3

1.4 High-strength or high-performance concrete 4

2 Introduction 

3 A historical perspective 22

3.1 Precursors and pioneers 22

3.2 From water reducers to superplasticizers 26

3.3 The arrival of silica fume 28

3.4 Present status 29

4 The high-performance concrete rationale 

4.1 Introduction 35

4.2 For the owner 36

4.3 For the designer 37

4.4 For the contractor 38

4.5 For the concrete producer 38

4.6 For the environment 40

4.7 Case studies 40

4.7.1 Water Tower Place 40

4.7.2 Gullfaks offshore platform 42

4.7.3 Sylans and Glacières viaducts 46

4.7.4 Scotia Plaza 50

4.7.5 Île de Ré bridge 53

4.7.6 Two Union Square 56

4.7.7 Joigny bridge 59viii Contents

4.7.8 Montée St-Rémi bridge 62

4.7.9 ‘Pont de Normandie’ bridge 66

4.7.10 Hibernia offshore platform 70

4.7.11 Confederation bridge 76

5 High-performance concrete principles 

5.1 Introduction 84

5.2 Concrete failure under compressive load 85

5.3 Improving the strength of hydrated cement paste 88

5.3.1 Porosity 89

5.3.2 Decreasing the grain size of hydration products 93

5.3.3 Reducing inhomogeneities 93

5.4 Improving the strength of the transition zone 93

5.5 The search for strong aggregates 95

5.6 Rheology of low water/binder ratio mixtures 96

5.6.1 Optimization of grain size distribution of aggregates 96

5.6.2 Optimization of grain size distribution of cementitious particles 97

5.6.3 The use of supplementary cementitious materials 97

5.7 The water/binder ratio law 97

5.8 Concluding remarks 99

6 Review of the relevant properties of some ingredients of high-performance concrete 

6.1 Introduction 101

6.2 Portland cement 101

6.2.1 Composition 101

6.2.2 Clinker manufacture 103

6.2.3 Clinker microstructure 106

6.2.4 Portland cement manufacture 111

6.2.5 Portland cement acceptance tests 113

6.2.6 Portland cement hydration 115

(a) Step 1 Mixing period 116

(b) Step 2 The dormant period 117

(c) Step 3 Initial setting 118

(d) Step 4 Hardening 119

(e) Step 5 Slowdown 120

6.2.7 Concluding remarks on Portland cement hydration from a high-performance concrete point of view 120

6.3 Portland cement and water 121

6.3.1 From water reducers to superplasticizers 122

6.3.2 Types of superplasticizer 126ix Contents

6.3.3 Manufacture of superplasticizers 126

(a) First step: sulfonation 126

(b) Second step: condensation 127

(c) Third step: neutralization 128

(d) Fourth step: filtration (in the case of calcium salt) 129

6.3.4 Portland cement hydration in the presence of superplasticizers 130

6.3.5 The crucial role of calcium sulfate 136

6.3.6 Superplasticizer acceptance 137

6.3.7 Concluding remarks 138

6.4 Supplementary cementitious materials 139

6.4.1 Introduction 139

6.4.2 Silica fume 140

6.4.3 Slag 147

6.4.4 Fly ash 152

6.4.5 Concluding remarks 155

7 Materials selection 

7.1 Introduction 162

7.2 Different classes of high-performance concrete 162

7.3 Materials selection 163

7.3.1 Selection of the cement 163

7.3.2 Selection of the superplasticizer 170

(a) Melamine superplasticizers 171

(b) Naphthalene superplasticizers 171

(c) Lignosulfonate-based superplasticizers 173

(d) Quality control of superplasticizers 173

7.3.3 Cement/superplasticizer compatibility 175

(a) The minislump method 176

(b) The Marsh cone method 178

(c) Saturation point 180

(d) Checking the consistency of the production

of a particular cement or superplasticizer 182

(e) Different rheological behaviours 183

(f) Practical examples 185

7.3.4 Superplasticizer dosage 189

(a) Solid or liquid form? 190

(b) Use of a set-retarding agent 190

(c) Delayed addition 190

7.3.5 Selection of the final cementitious system 190

7.3.6 Selection of silica fume 192

(a) Introduction 192

(b) Variability 192

(c) What form of silica fume to use 193

(d) Quality control 193

(e) Silica fume dosage 194

7.3.7 Selection of fly ash 195

(a) Quality control 196

7.3.8 Selection of slag 196

(a) Dosage rate 197

(b) Quality control 197

7.3.9 Possible limitations on the use of slag and fly ash in high-performance concrete 198

(a) Need for high early strength 198

(b) Cold weather concreting 198

(c) Freeze-thaw durability 199

(d) Decrease in maximum temperature 199

7.3.10 Selection of aggregates 199

(a) Fine aggregate 199

(b) Crushed stone or gravel 200

(c) Selection of the maximum size of coarse aggregate 202

7.4 Factorial design for optimizing the mix design of high-performance concrete 203

7.4.1 Introduction 203

7.4.2 Selection of the factorial design plan 204

7.4.3 Sample calculation 206

(a) Iso cement dosage curves 207

(b) Iso dosage curves for the superplasticizer 207

(c) Iso cost curves 208

7.5 Concluding remarks 210

8 High-performance mix design methods 

8.1 Background 215

8.2 ACI 211–1 Standard Practice for Selecting Proportions

for Normal, Heavyweight and Mass Concrete 216

8.3 Definitions and useful formulae 221

8.3.1 Saturated surface dry state for aggregates 221

8.3.2 Moisture content and water content 223

8.3.3 Specific gravity 225

8.3.4 Supplementary cementitious material content 225

8.3.5 Superplasticizer dosage 226

(a) Superplasticizer specific gravity 227

(b) Solids content 227

(c) Mass of water contained in a certain volume

of superplasticizer 228

(d) Other useful formulae 229xi Contents

(e) Mass of solid particles and volume needed 230

(f) Volume of solid particles contained in

(g) Sample calculation 230

8.3.6 Water reducer and air-entraining agent dosages 231

8.3.7 Required compressive strength 231

8.4 Proposed method 233

8.4.1 Mix design sheet 237

(a) Mix design calculations 239

(b) Sample calculation 241

(c) Calculations 241

8.4.2 From trial batch proportions to 1 m 3 composition (SSD conditions) 246

(a) Mix calculation 246

(b) Sample calculation 248

(c) Calculations 249

8.4.3 Batch composition 252

(a) Mix calculation 252

(b) Sample calculation 253

(c) Calculations 254

8.4.4 Limitations of the proposed method 255

8.5 Other mix design methods 257

8.5.1 Method suggested in ACI 363 Committee on high-strength concrete 257

8.5.2 de Larrard method (de Larrard, 1990) 259

8.5.3 Mehta and Aïtcin simplified method 261

9 Producing high-performance concrete 

9.1 Introduction 265

9.2 Preparation before mixing 267

9.3 Mixing 269

9.4 Controlling the workability of high-performance concrete 271

9.5 Segregation 272

9.6 Controlling the temperature of fresh concrete 272

9.6.1 Too cold a mix: increasing the temperature of fresh concrete 273

9.6.2 Too hot a mix: cooling down the temperature of fresh concrete 274

9.7 Producing air-entrained high-performance concretes 276

9.8 Case studies 278

9.8.1 Production of the concrete used to build the Jacques-Cartier bridge deck in Sherbrooke

(a) Concrete specifications 278xii Contents

(b) Composition of the high-performance concrete used 278

(c) Mixing sequence 279

(d) Economic considerations 280

9.8.2 Production of a high-performance concrete in a dry-batch plant 281

(a) Portneuf bridge (Lessard et al., 1993) 281

(b) Scotia Plaza building

(Ryell and Bickley, 1987) 282

10 Preparation for concreting: what to do, how to do it and when to do it 

10.1 Introduction 285

10.2 Preconstruction meeting 287

10.3 Prequalification test programme 288

10.3.1 Prequalification test programme for the construction of Bay-Adelaide Centre in Toronto,

Canada 289

10.3.2 Prequalification test programme for the 20 Mile Creek air-entrained high-performance concrete bridge on Highway 20 (Bickley, 1996) 290

10.3.3 Pilot test 291

10.4 Quality control at the plant 292

10.5 Quality control at the jobsite 293

10.6 Testing 294

10.6.1 Sampling 295

10.7 Evaluation of quality 295

10.8 Concluding remarks 297

11 Delivering, placing and controlling high-performance concrete 

11.1 High-performance concrete transportation 299

11.2 Final adjustment of the slump prior to placing 300

11.3 Placing high-performance concrete 301

11.3.1 Pumping 301

11.3.2 Vibrating 303

11.3.3 Finishing concrete slabs 304

11.4 Special construction methods 306

11.4.1 Mushrooming in column construction 306

11.4.2 Jumping forms 306

11.4.3 Slipforming 307

11.4.4 Roller-compacted high-performance concrete 309

11.5 Conclusion 309

12 Curing high-performance concrete to minimize shrinkage 

12.1 Introduction 311

12.2 The importance of appropriate curing 312

12.3 Different types of shrinkage 312

12.4 The hydration reaction and its consequences 313

12.4.1 Strength 315

12.4.2 Heat 316

12.4.3 Volumetric contraction 317

(a) Apparent volume and solid volume 317

(b) Volumetric changes of concrete (apparent volume) 318

(c) Chemical contraction (absolute volume) 319

(d) The crucial role of the menisci in concrete capillaries in apparent volume changes 320

(e) Essential difference between self-desiccation and drying 321

(f) From the volumetric changes of the hydrated cement paste to the shrinkage of concrete 321

12.5 Concrete shrinkage 322

12.5.1 Shrinkage of thermal origin 322

12.5.2 How to reduce autogenous and drying shrinkage and its effects by appropriate curing of high-performance concrete 323

12.6 Why autogenous shrinkage is more important in high-performance concrete than in usual concrete 324

12.7 Is the application of a curing compound sufficient to minimize or attenuate concrete shrinkage? 

12.8 The curing of high-performance concrete 327

12.8.1 Large columns 329

(a) Volumetric changes at A 329

(b) Volumetric changes at B 330

(c) Volumetric changes at C 331

12.8.2 Large beams 331

12.8.3 Small beams 332

12.8.4 Thin slabs 332

12.8.5 Thick slabs 333

12.8.6 Other cases 334

12.9 How to be sure that concrete is properly cured in the field 334

12.10 Conclusion 335

13 Properties of fresh concrete 338

13.1 Introduction 338

13.2 Unit mass 340

13.3 Slump 340xiv Contents

13.3.1 Measurement 340

13.3.2 Factors influencing the slump 341

13.3.3 Improving the rheology of fresh concrete 342

13.3.4 Slump loss 343

13.4 Air content 343

13.4.1 Non-air-entrained high-performance concrete 343

13.4.2 Air-entrained high-performance concrete 344

13.5 Set retardation 345

13.6 Concluding remarks 347

14 Temperature increase in high-performance concrete 349

14.1 Introduction 349

14.2 Comparison of the temperature increases within a 35 MPa concrete and a high-performance concrete 350

14.3 Some consequences of the temperature increase within a concrete 351

14.3.1 Effect of the temperature increase on the compressive strength of high-performance concrete 

14.3.2 Inhomogeneity of the temperature increase within a high-performance concrete structural element 353

14.3.3 Effect of thermal gradients developed during high-performance concrete cooling 353

14.3.4 Effect of the temperature increase on concrete microstructure 354

14.4 Influence of different parameters on the temperature increase 356

14.4.1 Influence of the cement dosage 357

14.4.2 Influence of the ambient temperature 360

14.4.3 Influence of the geometry of the structural element 361

14.4.4 Influence of the nature of the forms 363

14.4.5 Simultaneous influence of fresh concrete and ambient temperature 364

14.4.6 Concluding remarks 365

14.5 How to control the maximum temperature reached within a high-performance concrete structural element 366

14.5.1 Decrease of the temperature of the delivered concrete 366

(a) Liquid nitrogen cooling 367

(b) Use of crushed ice 367

14.5.2 Use of a retarder 367

14.5.3 Use of supplementary cementitious materials 

14.5.4 Use of a cement with a low heat of hydration 369

14.5.5 Use of hot water and insulated forms or heated and insulated blankets under winter conditions 

14.6 How to control thermal gradients 369

14.7 Concluding remarks 370

15 Testing high-performance concrete 

15.1 Introduction 

15.2 Compressive strength measurement 374

15.2.1 Influence of the testing machine 375

(a) Testing limitations due to the capacity of the testing machine 375

(b) Influence of the dimensions of the spherical head 377

(c) Influence of the rigidity of the testing machine 381

15.2.2 Influence of testing procedures 382

(a) How to prepare specimen ends 383

(b) Influence of eccentricity 388

15.2.3 Influence of the specimen 390

(a) Influence of the specimen shape 390

(b) Influence of the specimen mould 391

(c) Influence of the specimen diameter 392

15.2.4 Influence of curing 395

(a) Testing age 395

(b) How can high-performance concrete specimens be cured? 396

15.2.5 Core strength versus specimen strength 397

15.3 Stress-strain curve 398

15.4 Shrinkage measurement 400

15.4.1 Present procedure 401

15.4.2 Shrinkage development in a high water/binder concrete 402

15.4.3 Shrinkage development in a low water/binder concrete 402

15.4.4 Initial mass increase and self-desiccation 404

15.4.5 Initial compressive strength development and self-desiccation 404

15.4.6 New procedure for drying shrinkage measurement 405

15.5 Creep measurement 407

15.5.1 Present sample curing (ASTM C 512) 407

15.5.2 Development of different concrete deformations during a 28 day creep measurement 407xvi 

15.5.3 Deformations occurring in a high water/binder ratio concrete subjected to early loading during a creep test 408

15.5.4 Deformations occurring in a low water/binder ratio concrete subjected to early loading during a creep test 409

15.5.5 Proposed curing procedure before loading a concrete specimen for creep measurement 410

15.6 Concluding remarks on creep and shrinkage measurements 411

15.7 Permeability measurement 412

15.8 Elastic modulus measurement 415

16 Mechanical properties of high-performance concrete

16.1 Introduction 423

16.2 Compressive strength 425

16.2.1 Early-age compressive strength of high-performance concrete 426

16.2.2 Effect of early temperature rise of high-performance concrete on compressive strength 427

16.2.3 Influence of air content on compressive strength 428

16.2.4 Long-term compressive strength 429

16.3 Modulus of rupture and splitting tensile strength 431

16.4 Modulus of elasticity 433

16.4.1 Theoretical approach 433

16.4.2 Empirical approach 437

16.4.3 Concluding remarks on elastic modulus evaluation 440

16.5 Poisson’s ratio 442

16.6 Stress-strain curves 442

16.7 Creep and shrinkage 445

16.8 Fatigue resistance of high-performance concrete 448

16.8.1 Introduction 448

16.8.2 Definitions 450

(a) Wöhler diagrams 450

(b) Goodman diagrams 451

(c) Miner’s rule 451

16.8.3 Fatigue resistance of concrete structures 452

16.9 Concluding remarks 4534

17 The durability of high-performance concrete 

17.1 Introduction 458

17.2 The durability of usual concretes: a subject of major concern 460

17.2.1 Durability: the key criterion to good design 461xvii Contents

17.2.2 The critical importance of placing and curing in concrete durability 462

17.2.3 The importance of the concrete ‘skin’ 463

17.2.4 Why are some old concretes more durable than some modern ones? 466

17.3 Why high-performance concretes are more durable than usual concretes 467

17.4 Durability at a microscopic level 470

17.5 Durability at a macroscopic level 471

17.6 Abrasion resistance 472

17.6.1 Introduction 472

17.6.2 Factors affecting the abrasion resistance of high-performance concrete 473

17.6.3 Pavement applications 476

17.6.4 Abrasion-erosion in hydraulic structures 477

17.6.5 Ice abrasion 477

17.7 Freezing and thawing resistance 477

17.7.1 Freezing and thawing durability of usual concrete 478

17.7.2 Freezing and thawing durability of high-performance concrete 479

17.7.3 How many freeze-thaw cycles must a concrete sustain successfully before being said to be freeze-thaw resistant? 483

17.7.4 Personal views 484

17.8 Scaling resistance 485

17.9 Resistance to chloride ion penetration 486

17.10 Corrosion of reinforcing steel 487

17.10.1 Use of stainless steel rebars 489

17.10.2 Use of galvanized rebars 489

17.10.3 Use of epoxy-coated rebars 490

17.10.4 Use of glass fibre-reinforced rebars 491

17.10.5 Effectiveness of the improvement of ‘covercrete’ quality 492

(a) Time to initiate cracking 492

(b) Relationship between time to initiate

cracking and initial current 494

17.10.6 Concluding remarks 495

17.11 Resistance to various forms of chemical attack 496

17.12 Resistance to carbonation 497

17.13 Resistance to sea water 497

17.14 Alkali-aggregate reaction and high-performance concrete 497

17.14.1 Introduction 497

17.14.2 Essential conditions to see an AAR developing within a concrete 498xviii Contents

(a) Moisture condition and AAR 498

(b) Cement content, water/binder ratio and AAR 498

17.14.3 Superplasticizer and AAR 499

17.14.4 AAR prevention 499

17.14.5 Extrapolation of the results obtained on usual concrete to high-performance concrete 500

17.15 Resistance to fire 500

17.15.1 Is high-performance concrete a fire-resistant material? 500

17.15.2 The fire in the Channel Tunnel 502

(a) The circumstances 502

(b) The damage 503

17.16 Conclusions 503

18 Special high-performance concretes 

18.1 Introduction 510

18.2 Air-entrained high-performance concrete 511

18.2.1 Introduction 511

18.2.2 Design of an air-entrained high-performance concrete mix 512

(a) Sample calculation 512

18.2.3 Improvement of the rheology of high-performance concretes with entrained air 515

18.2.4 Concluding remarks 516

18.3 Lightweight high-performance concrete 516

18.3.1 Introduction 516

18.3.2 Fine aggregate 518

18.3.3 Cementitious systems 518

18.3.4 Mechanical properties 519

(a) Compressive strength 519

(b) Modulus of rupture, splitting strength and direct tensile strength 520

(c) Elastic modulus 520

(d) Bond strength 520

(e) Shrinkage and creep 520

(f) Post-peak behaviour 521

(g) Fatigue resistance 521

(h) Thermal characteristics 521

18.3.5 Uses of high-performance lightweight concrete 522

18.3.6 About the unit mass of lightweight concrete 522

18.3.7 About the absorption of lightweight aggregates 524

18.3.8 About the water content of lightweight aggregates when making concrete 525

18.3.9 Concluding remarks 526xix Contents

18.4 Heavyweight high-performance concrete 526

18.5 Fibre-reinforced high-performance concrete 527

18.6 Confined high-performance concrete 530

18.7 Roller-compacted high-performance concrete 534

18.8 Concluding remarks 540

19 Ultra high-strength cement-based materials 

19.1 Introduction 545

19.2 Brunauer et al. technique 549

19.3 DSP 549

19.4 MDF 550

19.5 RFC 551

20 A look ahead 556

20.1 Concrete: the most widely used construction material 556

20.2 Short-term trends for high-performance concrete 558

20.3 The durability market rather than only the high-strength market 560

20.4 Long-term trends for high-performance concrete 561

20.5 High-performance concrete competition 562

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Deep Excavation Theory and Practice

Deep Excavation Theory and Practice

Summary

Accelerating economic development and urbanization has led to engineers becoming increasingly ambitious, carrying out excavations in more difficult soils, so that excavations are deeper and more extensive. These complex conditions require advanced analysis, design methods and construction technologies. Most books on general foundation engineering introduce basic analysis and design of excavation, but do not usually deal with analysis and design in practice. This book covers both areas, introducing methods currently used in modern engineering, which can readily be applied to analysis and design in actual excavations. Based on interaction between research results, analysis and teaching experience, the book is suitable for both teachers and engineers in advanced analysis and design. Each chapter ends with a series of problems and solutions, making it equally useful as a textbook for senior undergraduate and graduate levels.

Table of Contents

Introduction

Soil Properties and Lateral Earth Pressures

Excavation Methods and Supporting System

Lateral Earth Pressure

Stability Analysis

Stress and Deformation Analysis – Simplified Method

Stress and Deformation Analysis – Beam on Elastic Foundation Method

Stress and Deformation Analysis – Finite Element Method

Dewatering of Excavations

Design of Structural Components

Excavation and Protection of Adjacent Buildings

Monitoring System

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SAFE 2016 Download

SAFE 2016 Download

SAFE is the ultimate tool for designing concrete floor and foundation systems. From framing layout all the way through to detail drawing production, SAFE integrates every aspect of the engineering design process in one easy and intuitive environment. SAFE provides unmatched benefits to the engineer with its truly unique combination of power, comprehensive capabilities, and ease-of-use.

Laying out models is quick and efficient with the sophisticated drawing tools, or use one of the import options to bring in data from CAD, spreadsheet, or database programs. Slabs or foundations can be of any shape, and can include edges shaped with circular and spline curves.

Mats and foundations can include nonlinear uplift from the soil springs, and a nonlinear cracked analysis is available for slabs. Generating pattern surface loads is easily done by SAFE with an automated option. Design strips can be generated by SAFE or drawn in a completely arbitrary manner by the user, with complete control provided for locating and sizing the calculated reinforcement. Finite element design without strips is also available and useful for slabs with complex geometries.

SAFE provides an immensely capable yet easy-to-use program for structural designers, provideing the only tool necessary for the modeling, analysis, design, and detailing of concrete slab systems and foundations.

SAFE 2016 Enhancements
Elasto-Plastic Behavior: Option to model elasto-plastic behavior for point, line and area (soil) springs now available.
Area Springs: Precedence now given to area springs applied through area objects with null properties. This allows spring properties to be overwritten over portions of large slab areas by using areas with null properties.
Modulus of Rupture for Cracked Deflection: Modulus of rupture for cracked deflection calculations can now be overwriten separately for each concrete material property. Previously a single overwrite applied to all concrete materials.
Tendons: Tendon vertical profile form redesigned for easy input and editing as the data for all spans of the tendon are now visible and editable at the same time.

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Pile Design and Construction Practice

Pile Design and Construction Practice

Contents

1 General principles and practices 1
1.1 Function of piles 1
1.2 Historical 1
1.3 Calculations of load-carrying capacity 2
1.4 Dynamic piling formulae 4
1.5 Code of practice requirements 5
1.6 Responsibilities of engineer and contractor 7
1.7 References 9

2 Types of pile 

2.1 Classification of piles 10
2.2 Driven displacement piles 14
2.3 Driven and cast-in-place displacement piles 50
2.4 Replacement piles 58
2.5 Composite piles 65
2.6 Minipiles and micropiles 66
2.7 Factors governing choice of type of pile 66
2.8 Reuse of existing piled foundations 69
2.9 References 69

3 Piling equipment and methods 

3.1 Equipment for driven piles 72
3.2 Equipment for installing driven and cast-in-place piles 104
3.3 Equipment for installing bored and cast-in-place piles 106
3.4 Procedure in pile installation 124
3.5 Constructing piles in groups 137
3.6 References 137

4 Calculating the resistance of piles to compressive loads 

4.1 General considerations 139
4.2 Calculations for piles in fine-grained soils 151
4.3 Piles in coarse-grained soils 165
4.4 Piles in soils intermediate between sands and clays 188
4.5 Piles in layered fine- and coarse-grained soils 189
4.6 The settlement of the single pile at the working load for piles in soil 192
4.7 Piles bearing on rock 196
4.8 Piles in fill – negative skin friction 212
4.9 References 220
4.10 Worked examples 223

5 Pile groups under compressive loading

5.1 Group action in piled foundations 240
5.2 Pile groups in fine-grained soils 243
5.3 Pile groups in coarse-grained soils 263
5.4 Eurocode 7 recommendations for pile groups 272
5.5 Pile groups terminating in rock 272
5.6 Pile groups in filled ground 276
5.7 Effects on pile groups of installation methods 278
5.8 Precautions against heave effects in pile groups 281
5.9 Pile groups beneath basements 282
5.10 The optimization of pile groups to reduce differential settlements in clay 287
5.11 References 288
5.12 Worked examples 290

6 The design of piled foundations to resist uplift and lateral loading 

6.1 The occurrence of uplift and lateral loading 305
6.2 Uplift resistance of piles 308
6.3 Single vertical piles subjected to lateral loads 327
6.4 Lateral loads on raking piles 352
6.5 Lateral loads on groups of piles 353
6.6 References 356
6.7 Worked examples 357

7 Some aspects of the structural design of piles and pile groups 

7.1 General design requirements 375
7.2 Designing reinforced concrete piles for lifting after fabrication 376
7.3 Designing piles to resist driving stresses 379
7.4 The effects on bending of piles below ground level 383
7.5 The design of axially loaded piles as columns 383
7.6 Lengthening piles 385
7.7 Bonding piles with caps and ground beams 386
7.8 The design of pile caps 388
7.9 The design of pile capping beams and connecting ground beams 393
7.10 References 396

8 Piling for marine structures

8.1 Berthing structures and jetties 398
8.2 Fixed offshore platforms 416
8.3 Pile installations for marine structures 418
8.4 References 424
8.5 Worked examples 425

9 Miscellaneous piling problems 

9.1 Piling for machinery foundations 434
9.2 Piling for underpinning 437
9.3 Piling in mining subsidence areas 445
9.4 Piling in frozen ground 449
9.5 Piled foundations for bridges on land 453
9.6 Piled foundations for over-water bridges 463
9.7 Piled foundations in karst 472
9.8 Energy piles 474
9.9 References 475
9.10 Worked example 477

10 The durability of piled foundations

10.1 General 478
10.2 Durability and protection of timber piles 479
10.3 Durability and protection of concrete piles 486
10.4 Durability and protection of steel piles 492
10.5 References 497
11 Ground investigations, piling contracts, pile testing 498
11.1 Ground investigations 498
11.2 Piling contracts and specifications 508
11.3 Control of pile installation 514
11.4 Load testing of piles 520
11.5 Tests for the structural integrity of piles 535
11.6 References 537
Appendix: properties of materials 539
A.1 Coarse-grained soils 539
A.2 Fine-grained and organic soils 539
A.3 Rocks and other materials 540
A.4 Engineering classification of chalk 540

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Foundation Engineering

Foundation Engineering

Contents

1. Review of Soil Mechanics Concepts and Analytical Techniques Used in Foundation Engineering
2. In Situ Soil Testing
3. Spread Footings: Analysis and Design
4. Geotechnical Design of Combined Spread Footings
5. Structural Design of Foundations
6. Design of Driven Piles and Pile Groups
7. Design of Drilled Shafts
8. Design of Laterally Loaded Piles
9. Construction Monitoring and Testing Methods of Driven Piles
10. Retaining Walls: Analysis and Design
11. Stability Analysis and Design of Slopes
12. Methods of Soft Ground Improvement
13. Impact of Groundwater on the Design of Earthen Structures

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Reinforced Concrete Design of Tall Buildings

Reinforced Concrete Design of Tall Buildings

Contents

1 Chapter    Design Concept 

1.1  Characteristics of Reinforced Concrete.......1
1.1.1  Confined Concrete .........1
1.1.2  Ductility4
1.1.3  Hysteresis ......................5
1.1.4  Redundancy ...................6
1.1.5  Detailing ........................6
1.2  Behavior of Reinforced Concrete Elements 7
1.2.1  Tension .7
1.2.2  Compression ..................7
1.2.3  Bending 8
1.2.3.1  Thumb Rules for Beam Design ...8
1.2.4  Shear ... 14
1.2.5  Sliding Shear (Shear Friction) ...... 18
1.2.6  Punching Shear ........... 21
1.2.7  Torsion 22
1.2.7.1  Elemental Torsion .........22
1.2.7.2  Overall Building Torsion ...........25
1.3  External Loads 26
1.3.1  Earthquakes Loads ......26
1.3.2  Wind Loads .................27
1.3.2.1  Extreme Wind Conditions .........29
1.3.3  Explosion Effects ......... 31
1.3.4  Floods .32
1.3.5  Vehicle Impact Loads ..32
1.4  Lateral Load-Resisting Systems ................32
1.4.1  Shear Walls ..................33
1.4.2  Coupled Shear Walls ...36
1.4.3  Moment-Resistant Frames ............37
1.4.4  Dual Systems ...............38
1.4.5  Diaphragm ...................38
1.4.6  Strength and Serviceability ..........39
1.4.7  Self-Straining Forces ...40
1.4.8  Abnormal Loads ..........40viii  Contents
1.5  Collapse Patterns ......................40
1.5.1  Earthquake Collapse Patterns ...... 41
1.5.1.1  Unintended Addition of Stiffness .... 41
1.5.1.2  Inadequate Beam Column Joint Strength .42
1.5.1.3  Tension/Compression Failures ...42
1.5.1.4  Wall-to-Roof Interconnection Failure .......43
1.5.1.5  Local Column Failure ...43
1.5.1.6  Heavy Floor Collapse ...44
1.5.1.7  Torsion Effects ..............44
1.5.1.8  Soft First-Story Collapse ...........45
1.5.1.9  Midstory Collapse .........45
1.5.1.10  Pounding ......45
1.5.1.11  P- Δ  Effect .....45
1.5.2  Collapse due to Wind Storms .......47
1.5.3  Explosion Effects .........47
1.5.4  Progressive Collapse ...47
1.5.4.1  Design Alternatives for Reducing Progressive Collapse .......49
1.5.4.2  Guidelines for Achieving Structural Integrity ....................49
1.5.5  Blast Protection of Buildings: The New SEI Standard ......................50
1.6  Buckling of a Tall Building under Its Own Weight 50
1.6.1  Circular Building ......... 51
1.6.1.1  Building Characteristics ............52
1.6.2  Rectangular Building .. 53
1.6.2.1  Building Characteristics ............ 53
1.6.3  Comments on Stability Analysis .. 53

2 Chapter    Gravity Systems

2.1  Formwork Considerations ........55
2.1.1  Design Repetition ........58
2.1.2  Dimensional Standards ................58
2.1.3  Dimensional Consistency .............59
2.1.4  Horizontal Design Techniques .....60
2.1.5  Vertical Design Strategy ..............63
2.2  Floor Systems ..65
2.2.1  Flat Plates ....................65
2.2.2  Flat Slabs .....................65
2.2.2.1  Column Capitals and Drop Panels ...66
2.2.2.2  Comments on Two-Way Slab Systems ......67
2.2.3  Waffl e Systems ............67
2.2.4  One-Way Concrete Ribbed Slabs .67
2.2.5  Skip Joist System .........67
2.2.6  Band Beam System .....68
2.2.7  Haunch Girder and Joist System ..70
2.2.8  Beam and Slab System 73
2.3  Design Methods ........................73
2.3.1  One-Way and Two-Way Slab Subassemblies ..73
2.3.2  Direct Design Method for Two-Way Systems . 74
2.3.3  Equivalent Frame Method ............ 75Contents  ix
2.3.4  Yield-Line Method ......77
2.3.4.1  Design Example: One-Way Simply Supported Slab ...........78
2.3.4.2  Yield-Line  Analysis of a Simply Supported Square Slab .. 81
2.3.4.3  Skewed Yield Lines ......82
2.3.4.4  Limitations of Yield-Line Method ...83
2.3.5  Deep Beams ................83
2.3.6  Strut-and-Tie Method ..85
2.4  One-Way Slab, T-Beams, and Two-Way Slabs: Hand Calculations ................92
2.4.1  One-Way Slab; Analysis by ACI 318-05 Provisions .92
2.4.2  T-Beam Design ............97
2.4.2.1  Design for Flexure ........97
2.4.2.2  Design for Shear .........100
2.4.3  Two-Way Slabs .......... 103
2.4.3.1  Two-Way Slab Design Example .....106
2.5  Prestressed Concrete Systems  108
2.5.1  Prestressing Methods  111
2.5.2  Materials .................... 111
2.5.2.1  Posttensioning Steel .... 111
2.5.2.2  Concrete ..... 112
2.5.3  PT Design .................. 113
2.5.3.1  Gravity Systems .......... 113
2.5.3.2  Design Thumb Rules .. 115
2.5.3.3  Building Examples ..... 118
2.5.4  Cracking Problems in Posttensioned Floors .120
2.5.5  Cutting of Prestressed Tendons .. 121
2.5.6  Concept of Secondary Moments 123
2.5.6.1  Secondary Moment Design Examples .....124
2.5.7  Strength Design for Flexure ....... 133
2.5.7.1  Strength Design Examples .......134
2.5.8  Economics of Posttensioning ..... 142
2.5.9  Posttensioned Floor Systems in High-Rise Buildings ..................... 143
2.5.9.1  Transfer Girder Example ......... 144
2.5.10  Preliminary Design of PT Floor Systems; Hand Calculations ........ 146
2.5.10.1  Preview ...... 146
2.5.10.2  Simple Span Beam ...... 149
2.5.10.3  Continuous Spans ....... 152
2.5.11  Typical Posttensioning Details ... 172
2.6  Foundations ... 172
2.6.1  Pile Foundations ........ 178
2.6.2  Mat Foundations ........ 179
2.6.2.1  General Considerations ............ 179
2.6.2.2  Analysis ..... 182
2.6.2.3  Mat for a 25-Story Building .... 183
2.6.2.4  Mat for an 85-Story Building .. 185
2.7  Guidelines for Thinking on Your Feet .... 187
2.8  Unit Quantities ........................ 187
2.8.1  Unit Quantity of Reinforcement in Columns  188
2.8.2  Unit Quantity of Reinforcement and Concrete in Floor Framing Systems .......197

3 Chapter    Lateral Load-Resisting Systems 

3.1  Flat Slab-Frame System ......... 201
3.2  Flat Slab-Frame with Shear Walls ...........203
3.3  Coupled Shear Walls ..............204
3.4  Rigid Frame ...205
3.4.1  Defl ection Characteristics ..........207
3.4.1.1  Cantilever Bending Component .....207
3.4.1.2  Shear Racking Component ......207
3.5  Tube System with Widely Spaced Columns ......... 210
3.6  Rigid Frame with Haunch Girders .......... 210
3.7  Core-Supported Structures ..... 212
3.8  Shear Wall–Frame Interaction ................ 212
3.8.1  Behavior .................... 217
3.8.2  Building Examples .... 218
3.9  Frame Tube System ................224
3.9.1  Behavior ....................225
3.9.2  Shear Lag...................225
3.9.3  Irregular Tube ............229
3.10  Exterior Diagonal Tube ..........230
3.10.1  Example of Exterior Diagonal Tube: Onterie Center, Chicago ........ 231
3.11  Bundled Tube .232
3.11.1  Example of Bundled Tube: One Magnifi cent Mile, Chicago ...........232
3.12  Spinal Wall Systems ...............234
3.13  Outrigger and Belt Wall System ..............234
3.13.1  Defl ection Calculations ..............238
3.13.1.1  Case 1: Outrigger Wall at the Top .238
3.13.1.2  Case 2: Outrigger Wall at Quarter Height from the Top .......239
3.13.1.3  Case 3: Outrigger Wall at Midheight ....... 241
3.13.1.4  Case 4: Outrigger Wall at Quarter Height from the Bottom . 241
3.13.2  Optimum Location of a Single Outrigger Wall .......242
3.13.3  Optimum Locations of Two Outrigger Walls 247
3.13.4  Recommendations for Optimum Locations ..250
3.14  Miscellaneous Systems ........... 251

4  Chapter  Wind Loads 

4.1  Design Considerations ............ 253
4.2  Natural Wind .255
4.2.1  Types of Wind ...........256
4.3  Characteristics of Wind ..........256
4.3.1  Variation of Wind Velocity with Height (Velocity Profi le) ..............257
4.3.2  Wind Turbulence .......258
4.3.3  Probabilistic Approach ...............260
4.3.4  Vortex Shedding ........ 261
4.3.5  Dynamic Nature of Wind ...........264
4.3.6  Pressures and Suctions on Exterior Surfaces 264
4.3.6.1  Scaling .......264
4.3.6.2  Internal Pressures and Differential Pressures ..................265
4.3.6.3  Distribution of Pressures and Suctions ....265
4.3.6.4  Local Cladding Loads and Overall Design Loads ...........266Contents  xi
4.4  ASCE 7-05: Wind Load Provisions .........267
4.4.1  Analytical Procedure—Method 2, Overview .........273
4.4.2  Method 2: Step-by-Step Procedure ......... 274
4.4.2.1  Wind Speedup over Hills and Escarpments: Factor ....280
4.4.2.2  Gust Effect Factor ....... 281
4.4.2.3  Determination of Design Wind Pressures Using Graphs ........289
4.4.2.4  Along-Wind Response 292
4.4.2.5  Worksheet for Calculation of Gust Effect Factor Along-Wind Displacement and Acceleration
4.4.2.6  Comparison of Gust Effect Factor and Along-Wind Response ....299
4.4.2.7  One More Example: Design Wind Pressures for Enclosed Building, Method 2 ... 301
4.5  National Building Code of Canada (NBCC 2005): Wind Load Provisions ....304
4.5.1  Static Procedure ........304
4.5.1.1  Specified Wind Load ..304
4.5.1.2  Exposure Factor
4.5.1.3  Gust Factors,
4.5.1.4  Pressure Coefficient,
4.5.2  Dynamic Procedure ...306
4.5.2.1  Gust Effect Factor,(Dynamic Procedure)
4.5.2.2  Design Example: Calculations for Gust Effect
4.5.2.3  Wind-Induced Building Motion .... 311
4.5.2.4  Design Example .......... 312
4.5.2.5  Comparison of Along-Wind and Across-Wind Accelerations .............. 314
4.5.3  Wind Load Comparison among International Codes and Standards ............ 315
4.6  Wind-Tunnels . 315
4.6.1  Types of Wind-Tunnel Tests .......320
4.6.1.1  Rigid Pressure Model . 321
4.6.1.2  High-Frequency Base Balance and High-Frequency Force Balance (HFBB/HFFB Model)
4.6.1.3  Aeroelastic Model .......324
4.6.1.4  Multidegree-of-Freedom Aeroelastic Model ....................330
4.6.1.5  Option for Wind-Tunnel Testing .... 331
4.6.1.6  Lower Limit on Wind-Tunnel Test Results ....................... 331
4.6.2  Prediction of Acceleration and Human Comfort .... 331
4.6.3  Load Combination Factors ......... 332
4.6.4  Pedestrian Wind Studies ............ 332
4.6.5  Motion Perception: Human Response to Building Motions ............ 335
4.6.6  Structural Properties Required for Wind-Tunnel Data Analysis ............ 335
4.6.6.1  Natural Frequencies .... 336
4.6.6.2  Mode Shapes ............... 336
4.6.6.3  Mass Distribution ....... 337
4.6.6.4  Damping Ratio ............ 337
4.6.6.5  Miscellaneous Information ...... 338
4.6.6.6  Example ..... 338
4.6.7  Period Determination and Damping Values for Wind Design ......... 341

5  Chapter  Seismic Design

5.1  Building Behavior ...................349
5.1.1  Infl uence of Soil ........349
5.1.2  Damping ....................350
5.1.3  Building Motions and Defl ections ........... 352
5.1.4  Building Drift and Separation .... 352
5.2  Seismic Design Concept ......... 353
5.2.1  Structural Response .. 353
5.2.2  Load Path .................. 353
5.2.3  Response of Elements Attached to Buildings .........354
5.2.4  Adjacent Buildings ....354
5.2.5  Irregular Buildings .... 355
5.2.6  Lateral Force–Resisting Systems ............ 356
5.2.7  Diaphragms ............... 357
5.2.8  Ductility..................... 358
5.2.9  Damage Control Features ...........360
5.2.10  Continuous Load Path ................ 361
5.2.11  Redundancy ............... 361
5.2.12  Confi guration .............362
5.2.13  Dynamic Analysis .....364
5.2.13.1  Response-Spectrum Method...367
5.2.13.2  Response-Spectrum Concept .. 371
5.2.13.3  Deformation Response Spectrum . 372
5.2.13.4  Pseudo-Velocity Response Spectrum ..... 373
5.2.13.5  Pseudo-Acceleration Response Spectrum ....................... 374
5.2.13.6  Tripartite Response Spectrum: Combined Displacement–Velocity–Acceleration (DVA) Spectrum ... 374
5.2.13.7  Characteristics of Response Spectrum ... 379
5.3  An Overview of 2006 IBC ..... 381
5.3.1  Occupancy Category . 381
5.3.2  Overturning, Uplifting, and Sliding ........383
5.3.3  Seismic Detailing ......383
5.3.4  Live-Load Reduction in Garages ............384
5.3.5  Torsional Forces ........384
5.3.6  Partition Loads ..........384
5.4  ASCE 7-05 Seismic Provisions: An Overview.....384
5.5   An Overview of Chapter 11 of ASCE 7-05, Seismic Design Criteria ...........386
5.5.1  Seismic Ground-Motion Values .386
5.5.1.1  Site Coefficients
5.5.1.2  Site Class ....389
5.5.1.3  Design Response Spectrum ......389
5.5.2  Equivalent Lateral Force Procedure ........390
5.5.2.1  Parameters S
5.5.2.2  Site-Specifi Ground Motion Analysis .....397
5.5.3  Importance Factor and Occupancy Category 398
5.5.3.1  Importance Factor
5.5.3.2  Occupancy Categories .399
5.5.4  Seismic Design Category ...........400
5.5.5  Design Requirements for SDC A Buildings .401
5.5.6  Geologic Hazards and Geotechnical Investigation .404Contents  xiii
5.5.7  Base Shear for Preliminary Design .........405
5.5.8  Design Response Spectrum for Selected Cities in the U.S.A. ......... 414
5.6  An Overview of Chapter 12 of ASCE 7-05, Seismic Design Requirements for Building Structures .....427
5.6.1  Seismic Design Basis 427
5.6.2  Structural System Selection .......427
5.6.3  Diaphragms ...............429
5.6.3.1  Irregularities ...............430
5.6.4  Seismic Load Effects and Combinations 430
5.6.5  Direction of Loading . 431
5.6.6  Analysis Procedure ... 432
5.6.7  Modeling Criteria ...... 432
5.6.8  Modal Analysis ......... 433
5.6.9  Diaphragms, Chords, and Collectors ...... 433
5.6.10  Structural Walls and Their Anchorage ...434
5.6.11  Drift and Deformation ................ 435
5.6.12  Foundation Design .... 436
5.6.12.1  Foundation Requirements for Structures Assigned to Seismic Design Category C . 437
5.6.12.2  Foundation Requirements for Structures Assigned to Seismic Design Categories
5.7  ASCE 7-05, Seismic Design: An In-Depth Discussion ........ 438
5.7.1  Seismic Design Basis  439
5.7.2  Structural System Selection .......440
5.7.2.1  Bearing Wall System ..440
5.7.2.2  Building Frame System ........... 441
5.7.2.3  Moment Frame System ............ 441
5.7.2.4  Dual System ................ 441
5.7.3  Special Reinforced Concrete Shear Wall 442
5.7.4  Detailing Requirements .............442
5.7.5  Building Irregularities ................443
5.7.5.1  Plan or Horizontal Irregularity 446
5.7.5.2  Vertical Irregularity ....448
5.7.6  Redundancy ...............448
5.7.7  Seismic Load Combinations .......449
5.7.7.1  Seismic Load Effect ....450
5.7.7.2  Seismic Load Effect with Overstrength .. 451
5.7.7.3  Elements Supporting Discontinuous Walls or Frames .......... 451
5.7.8  Direction of Loading . 451
5.7.9  Analysis Procedures .. 452
5.7.9.1  Equivalent Lateral-Force Procedure ........ 455
5.7.9.2  Modal Response Spectrum Analysis .......463
5.7.10  Diaphragms, Chords, and Collectors ......464
5.7.10.1  Diaphragms for SDC A ...........465
5.7.10.2  Diaphragms for SDCs B through F .........465
5.7.10.3  General Procedure for Diaphragm Design .......................465
5.7.11  Catalog of Seismic Design Requirements ..... 473
5.7.11.1  Buildings in SDC A .... 473
5.7.11.2  Buildings in SDC B .... 474xiv  Contents
5.7.11.3  Buildings in SDC C .... 475
5.7.11.4  Buildings in SDC D .... 476
5.7.11.5  Buildings in SDC E .... 478
5.7.11.6  Buildings in SDC F ..... 478
5.8  Seismic Design Example: Dynamic Analysis Procedure (Response Spectrum Analysis) Using Hand Calculations ..... 478
5.9  Anatomy of Computer Response Spectrum Analyses (In Other Words, What Goes on in the Black Box) .............487
5.10  Dynamic Response Concept ...497
5.10.1  Difference between Static and Dynamic Analyses .500
5.10.2  Dynamic Effects due to Wind Loads ......503
5.10.3  Seismic Periods .........504
5.11  Dynamic Analysis Theory .....505
5.11.1  Single-Degree-of-Freedom Systems .......505
5.11.2  Multi-Degree-of-Freedom Systems .........508
5.11.3  Modal Superposition Method ..... 511
5.11.4  Normal Coordinates .. 511
5.11.5  Orthogonality ............ 512
5.12  Summary ....... 518

6 Chapter    Seismic Design Examples and Details 

6.1  Seismic Design Recap ............ 523
6.2  Design Techniques to Promote Ductile Behavior 526
6.3  Integrity Reinforcement ......... 529
6.4  Review of Strength Design ..... 530
6.4.1  Load Combinations ... 532
6.4.2  Earthquake Load E .... 532
6.4.2.1  Load Combination for Verifying Building Drift .............. 534
6.4.3  Capacity Reduction Factors,  φ.... 534
6.5  Intermediate Moment-Resisting Frames . 535
6.5.1  General Requirements: Frame Beams .... 535
6.5.2  Flexural and Transverse Reinforcement: Frame Beams .................. 535
6.5.3  Transverse Reinforcement: Frame Columns . 537
6.5.4  Detailing Requirements for Two-Way Slab Systems without Beams ........................ 538
6.6  Special Moment-Resisting Frames .......... 539
6.6.1  General Requirements: Frame Beams .... 539
6.6.2  Flexural Reinforcement: Frame Beams ..540
6.6.3  Transverse Reinforcement: Frame Beams .... 541
6.6.4  General Requirements: Frame Columns . 541
6.6.5  Flexural Reinforcement: Frame Columns ..... 541
6.6.6  Transverse Reinforcement: Frame Columns .544
6.6.7  Transverse Reinforcement: Joints ...........546
6.6.8  Shear Strength of Joint ...............546
6.6.9  Development of Bars in Tension 548
6.7  Shear Walls ....548
6.7.1  Minimum Web Reinforcement: Design for Shear ..548
6.7.2  Boundary Elements ...549
6.7.3  Coupling Beams ........ 550
6.8  Frame Members Not Designed to Resist Earthquake Forces ........................ 551
6.9  Diaphragms ... 552
  6.9.1  Minimum Thickness and Reinforcement .... 552
  6.9.2  Shear Strength ......... 552
  6.9.3  Boundary Elements . 553
6.10  Foundations ... 553
  6.10.1  Footings, Mats, and Piles ......... 553
  6.10.2  Grade Beams and Slabs-on-Grade ........554
  6.10.3  Piles, Piers, and Caissons .........554
6.11  Design Examples ....................554
  6.11.1   Frame Beam Example: Ordinary Reinforced Concrete Moment Frame ........ 555
  6.11.2   Frame Column Example: Ordinary Reinforced Concrete Moment Frame ........ 557
  6.11.3   Frame Beam Example: Intermediate Reinforced Concrete Moment Frame ........ 559
  6.11.4   Frame Column Example: Intermediate Reinforced Concrete Moment Frame ........ 561
  6.11.5  Shear Wall Example: Seismic Design Category A, B, or C ...........563
  6.11.6   Frame Beam Example: Special Reinforced Concrete Moment Frame ........565
  6.11.7   Frame Column Example: Special Reinforced Concrete Moment Frame ........ 570
  6.11.8   Beam–Column Joint Example: Special Reinforced Concrete Frame ....... 574
  6.11.9  Special Reinforced Concrete Shear Wall ....577
  6.11.9.1  Preliminary Size Determination  579
  6.11.9.2  Shear Design ........... 579
  6.11.9.3  Shear Friction (Sliding Shear) ...580
  6.11.9.4  Longitudinal Reinforcement  581
  6.11.9.5  Web Reinforcement  581
  6.11.9.6  Boundary Elements  583
  6.11.10  Special Reinforced Concrete Coupled Shear Walls .......................587
  6.11.10.1  Coupling Beams .....588
  6.11.10.2  Wall Piers ...............593
6.12  Typical Details ........................599
6.13  ACI 318-08 Update .................600
  6.13.1  Outline of Major Changes ........600
  6.13.2  Summary of Chapter 21, ACI 318-08 ....605
  6.13.3  Analysis and Proportioning of Structural Members ......................605
  6.13.4   Reinforcement in Special Moment Frames and Special Structural Walls .......605
  6.13.5   Mechanical Splices in Special Moment Frames and Special Structural Walls .......606
  6.13.6   Welded Splices in Special Moment Frames and Special Structural Walls .......606
  6.13.7  Ordinary Moment Frames, SDC B .......606
  6.13.8  Intermediate Moment Frames ..606
  6.13.9  Two-Way Slabs without Beams 607
  6.13.10   Flexural Members (Beams) of Special Moment Frames ...............607
  6.13.11  Transverse Reinforcement ........608
  6.13.12  Shear Strength Requirements ...609xvi  Contents
  6.13.13   Special Moment Frame Members Subjected to Bending and Axial Loads ......609
  6.13.14  Shear Strength Requirements for Columns . 611
  6.13.15  Joints of Special Moment Frames ......... 611
  6.13.16  Special Structural Walls and Coupling Beams ..... 611
  6.13.17  Shear Wall Design for Flexure and Axial Loads .. 612
  6.13.18  Boundary Elements of Special Structural Walls ... 613
  6.13.19  Coupling Beams ...... 613

7 Chapter    Seismic Rehabilitation of Existing Buildings

7.1  Code-Sponsored Design ......... 619
7.2  Alternate Design Philosophy .. 619
7.3  Code Provisions for Seismic Upgrade ..... 621
7.4  Building Deformations ...........622
7.5  Common Defi ciencies and Upgrade Methods ......623
7.5.1  Diaphragms ...............624
7.5.1.1  Cast-in-Place Concrete Diaphragms ........624
7.5.1.2  Precast Concrete Diaphragms .627
7.5.2  Shear Walls ................627
7.5.2.1  Increasing Wall Thickness ......627
7.5.2.2  Increasing Shear Strength of Wall .628
7.5.2.3  Infi lling between Columns ......628
7.5.2.4  Addition of Boundary Elements ....628
7.5.2.5  Addition of Confi nement Jackets ...629
7.5.2.6  Repair of Cracked Coupling Beams ........629
7.5.2.7  Adding New Walls ......629
7.5.2.8  Precast Concrete Shear Walls ..629
7.5.3  Infi lling of Moment Frames .......629
7.5.4  Reinforced Concrete Moment Frames ....630
7.5.5  Open Storefront ......... 631
7.5.6  Clerestory .................. 631
7.5.7  Shallow Foundations . 632
7.5.8  Rehabilitation Measures for Deep Foundations ...... 632
7.5.9  Nonstructural Elements .............. 633
7.5.9.1  Nonload-Bearing Walls ........... 633
7.5.9.2  Precast Concrete Cladding ...... 633
7.5.9.3  Stone or Masonry Veneers .......634
7.5.9.4  Building Ornamentation ..........634
7.5.9.5  Acoustical Ceiling ......634
7.6  Seismic Rehabilitation of Existing Buildings, ASCE / SEI 41-06 ..................634
7.6.1  Overview of Performance Levels ............ 641
7.6.2  Permitted Design Methods .........642
7.6.3  Systematic Rehabilitation ...........643
7.6.3.1  Determination of Seismic Ground Motions .....................644
7.6.3.2  Determination of As-Built Conditions ....644
7.6.3.3  Primary and Secondary Components ......645
7.6.3.4  Setting Up Analytical Model and Determination of Design Forces .............645
7.6.3.5  Ultimate Load Combinations: Combined Gravity and Seismic Demand .........647
7.6.3.6  Component Capacity Calculations
7.6.3.7  Capacity versus Demand Comparisons ...649
7.6.3.8  Development of Seismic Strengthening Strategies ........... 651
7.6.4  ASCE / SEI 41-06: Design Example ......... 661
7.6.4.1   Dual System: Moment Frames and Shear Walls .............. 661
7.6.5  Summary of ASCE / SEI 41-06 ...666
7.7  Fiber-Reinforced Polymer Systems for Strengthening of Concrete Buildings ........667
7.7.1  Mechanical Properties and Behavior ......667
7.7.2  Design Philosophy .....668
7.7.3  Flexural Design .........668
7.8  Seismic Strengthening Details ................668
7.8.1  Common Strategies for Seismic Strengthening ......669

8 Chapter    Tall Buildings 

8.1  Historical Background ............688
8.2  Review of High-Rise Architecture ..........692
8.3  Functional Requirements ........694
8.4  Defi nition of Tall Buildings ....695
8.5  Lateral Load Design Philosophy .............695
8.6  Concept of Premium for Height ..............696
8.7  Relative Structural Cost ..........697
8.8  Factors for Reduction in the Weight of Structural Frame ....697
8.9  Development of High-Rise Architecture .699
  8.9.1  Architect–Engineer Collaboration ........704
  8.9.2  Sky Scraper Pluralism ..............704
  8.9.3  Structural Size .........705
8.10  Structural Scheme Options .....705
  8.10.1  Space Effi ciency of High-Rise Building Columns  716
  8.10.2  Structural Cost and Plan Density Comparison ..... 717
8.11  Summary of Building Technology .......... 718
8.12  Structural Concepts ................ 719
8.13  Bending and Shear Rigidity Index ..........720
8.14  Case Studies...724
  8.14.1  Empire State Building, New York, City, New York .......................724
  8.14.2  South Walker Tower, Chicago, Illinois .724
  8.14.3  Miglin-Beitler Tower, Chicago, Illinois 726
  8.14.4  Trump Tower, Chicago, Illinois ............730
  8.14.4.1  Vital Statistics .......... 731
  8.14.5  Jin Mao Tower, Shanghai, China .......... 731
  8.14.6  Petronas Towers, Malaysia .......734
  8.14.7  Central Plaza, Hong Kong ........736
  8.14.8  Singapore Treasury Building ... 739
  8.14.9  City Spire, New York City ........ 740
  8.14.10  NCNB Tower, North Carolina .. 740
  8.14.11  Museum Tower, Los Angeles, California .... 743
  8.14.12  MGM City Center, Vdara Tower, Las Vegas, Nevada ....................744
  8.14.13  Citybank Plaza, Hong Kong ..... 746
  8.14.14  Trump Tower, New York .......... 746xviii  Contents
  8.14.15  Two Prudential Plaza, Chicago, Illinois  747
  8.14.16  Cent Trust Tower, Miami, Florida ......... 749
  8.14.17  Metropolitan Tower, New York City ..... 751
  8.14.18  Carnegie Hall Tower, New York City ... 752
  8.14.19  Hopewell Center, Hong Kong .. 753
  8.14.20  Cobalt Condominiums, Minneapolis, Minnesota . 754
  8.14.21  The Cosmopolitan Resort & Casino, Las Vegas, Nevada .............. 757
  8.14.22  Elysian Hotel and Private Residences, Chicago, Illinois ............... 759
  8.14.22.1  Foundations ............ 759
  8.14.22.2  Floor Systems .........760
  8.14.22.3  Gravity System ....... 761
  8.14.22.4  Lateral System ....... 761
  8.14.22.5  Tuned Liquid Damper ......... 761
  8.14.23   Shangri-La New York (610 Lexington Avenue), New York ................. 762
  8.14.24   Millennium Tower, 301 Mission Street, San Francisco, California ......... 768
  8.14.25  Al Bateen Towers, Dubai, UAE ............773
  8.14.25.1  Wind Loads ............777
  8.14.25.2  Seismic Loads ........778
  8.14.26  SRZ Tower, Dubai, UAE ..........778
  8.14.26.1  Wind Loads ............779
  8.14.26.2  Seismic Loads ........ 782
  8.14.26.3  Computer Model .... 782
  8.14.26.4  Building Behavior .. 783
  8.14.26.5  Wind ...... 783
  8.14.27  The Four Seasons Hotel and Tower, Miami, Florida ..................... 783
  8.14.28  Burj Dubai ...............786
8.15  Future of Tall Buildings ......... 791

9 Chapter    Special Topics

9.1  Damping Devices for Reducing Motion Perception ....793
9.1.1  Passive Viscoelastic Dampers ......793
9.1.2  Tuned Mass Damper ...795
9.1.2.1  Citicorp Tower, New York ........796
9.1.2.2  John Hancock Tower, Boston, Massachusetts ...................798
9.1.2.3  Design Considerations for TMD ....799
9.1.3  Sloshing Water Damper ...............799
9.1.4  Tuned Liquid Column Damper ....799
9.1.4.1  Wall Center, Vancouver, British Columbia ........................800
9.1.4.2  Highcliff Apartment Building, Hong Kong .......................800
9.1.5  Simple Pendulum Damper ...........800
9.1.5.1  Taipei Financial Center 802
9.1.6  Nested Pendulum Damper ...........803
9.2  Seismic Isolation ......................804
9.2.1  Salient Features ..........806
9.2.2  Mechanical Properties of Seismic Isolation Systems ........................808
9.2.3  Elastomeric Isolators ..808
9.2.4  Sliding Isolators .......... 810
9.2.5  Seismically Isolated Structures: ASCE 7-05 Design Provisions ....... 810
9.2.5.1  Equivalent Lateral Force Procedure ......... 813
9.2.5.2  Lateral Displacements . 813
9.2.5.3  Minimum Lateral Forces for the Design of Isolation System and Structural Elements at or below Isolation System .......... 816
9.2.5.4  Minimum Lateral Forces for the Design of Structural Elements above Isolation System .. 816
9.2.5.5  Drift Limits . 817
9.2.5.6  Illustrative Example: Static Procedure ..... 817
9.3  Passive Energy Dissipation ......829
9.4  Preliminary Analysis Techniques ..............830
  9.4.1  Portal Method ........... 833
  9.4.2  Cantilever Method ....834
  9.4.3  Lateral Stiffness of Frames ........837
  9.4.4  Framed Tube Structures .............845
9.5  Torsion ...846
  9.5.1  Preview......................846
  9.5.2  Concept of Warping Behavior ...857
  9.5.3  Sectorial Coordinate  ω¢ ............. 861
  9.5.4  Shear Center ..............863
9.5.4.1  Evaluation of Product Integrals 865
  9.5.5  Principal Sectorial Coordinate Diagram..865
9.5.5.1  Sectorial Moment of Inertia
  9.5.6  Torsion Constant J ....865
  9.5.7  Calculation of Sectorial Properties: Worked Example ....................866
  9.5.8  General Theory of Warping Torsion .......867
9.5.8.1  Warping Torsion Equations for Shear Wall Structures ......870
  9.5.9  Torsion Analysis of Shear Wall Building: Worked Example........... 871
  9.5.10  Warping Torsion Constants for Open Sections ....... 881
  9.5.11  Stiffness Method Using Warping-Column Model ..883
9.6  Performance-Based Design ......885
  9.6.1  Design Ideology ........885
  9.6.2  Performance-Based Engineering ............886
  9.6.3  Linear Response History Procedure .......887
  9.6.4  Nonlinear Response History Procedure .887
  9.6.5  Member Strength ......888
  9.6.6  Design Review ..........888
  9.6.7  New Building Forms .889
9.7  Wind Defl ections ......................890
9.8  2009 International Building Code (2009 IBC) Updates .........892
  9.8.1  An Overview of Structural Revisions .....892
9.8.1.1  Earthquake Loads ........892
9.8.1.2  Wind Loads .892
9.8.1.3  Structural Integrity ......893
9.8.1.4  Other Updates in Chapter 16 ....893
9.8.1.5  Chapter 18: Soils and Foundations .893
9.8.1.6  Chapter 19: Concrete ...893
  9.8.2  Detail Discussion of Structural Revisions ....893
9.8.2.1  Section 1604.8.2: Walls ............893
9.8.2.2  Section 1604.8.3: Decks ...........894
9.8.2.3  Section 1605.1.1: Stability .......894
9.8.2.4  Sections 1607.3 and 1607.4: Uniformly Distributed Live Loads and Concentrated Live Loads
9.8.2.5  Section 1607.7.3: Vehicle Barrier Systems .......................894
9.8.2.6  Section 1607.9.1.1: One-Way Slabs ........894
9.8.2.7   Section 1609.1.1.2: Wind Tunnel Test Limitations ...........894
9.8.2.8  Section 1613.7: ASCE 7-05, Section 11.7.5: Anchorage of Walls .....897
9.8.2.9  Section 1607.11.2.2: Special Purpose Roofs ....................897
9.8.2.10  Section 1613: Earthquake Loads ...897
9.8.2.11   Minimum Distance for Building Separation .....................898
9.8.2.12  Section 1613.6.7: Minimum Distance for Building Separation ..899
9.8.2.13  Section 1614: Structural Integrity ..899
9.8.3  Chapter 17: Structural Tests and Special Inspections ........................900
9.8.3.1  Section 1704.1: General ...........900
9.8.3.2  Section 1704.4: Concrete Construction....900
9.8.3.3  Section 1704.10: Helical Pile Foundations .......................900
9.8.3.4  Section 1706: Special Inspections for Wind Requirements ..............900
9.8.4  Chapter 18: Soils and Foundations ...........900
9.8.4.1  Section 1803: Geotechnical Investigations .......................900
9.8.4.2  Section 1807.2.3: Safety Factor 900
9.8.4.3  Section 1808.3.1: Seismic Overturning ...901
9.8.4.4   Sections 1810.3.1.5 and 1810.3.5.3.3: Helical Piles ...........901
9.8.5  Chapter 19: Concrete ..901
9.8.5.1  Section 1908.1: General ...........901
9.8.5.2  Section 1908.1.9: ACI 318, Section D.3.3 901
9.8.5.3  Sections 1909.6.1 and 1909.6.3: Basement Walls and Openings in Walls ......901
9.8.6  Anticipated Revisions in 2012 IBC ..........901

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