Structural Design of Buildings

Acknowledgements xiii About the Author xv Introduction xvii Chapter 1 The History of Buildings 1 The development of building knowledge 1 Styles of architecture and building construction 2 Chapter 2 Loadings and Aspects of Structural Theory Relating to Buildings 19 Weight and mass 19 Permanent actions or dead loads 19 Variable actions or imposed loads 20 Wind load 20 Accidental actions 26 Seismic action 26 BS EN 1991: Actions on structures EC1 26 Combinations of load and factors of safety 26 Stress 27 Strain 27 Young's modulus or modulus of elasticity 27 Plastic deformation 27 Buckling 29 Local buckling 29 Second moment of area 29 Centre of gravity 30 Lateral torsional buckling 30 Neutral axis 30 Bending force 30 Shear force and bending moment 31 Deflection 31 Static equilibrium 31 Internal forces 32 Derivation of shear force 35 Derivation of bending moment 35 Derivation of deflection 36 Basic theory of bending 37 Moment of resistance 39 Combined bending and direct stress 40 External and internal statically determinate structures 40 Connections and restraints 41 Stiffness 44 Buildings and load paths 45 Chapter 3 The Construction of Buildings 49 Breathable and non-breathable construction 49 Timber frame 51 Stone 64 Modern timber frame construction 81 Solid brick construction 81 Cavity construction 82 Steel construction 84 Commercial steel portal frames 87 Precast concrete construction 88 Chapter 4 Steel 93 Steel properties 93 Lateral torsional buckling 93 The effect of end restraints on a beam 93 Bending failure 101 Local buckling 101 Shear failure 102 Web bearing and buckling 102 Deflection 102 Fire and corrosion 102 Chapter 5 Concrete 105 The history of cement and concrete 105 Cement 105 Water and workability - now known as consistence 106 Failure of concrete 107 Strength of concrete 109 Concrete mix designs 109 Creep 111 Environment 111 Air-entrained concrete 111 Accelerators and retarders 112 Plasticizers 112 Fly ash, silica flume and ground granulated blast furnace slag 112 Anti-corrosion 112 Chapter 6 Timber 113 Grading of timber 113 Moisture 113 Air-dried timber 119 Kiln-dried timber 119 Dimensions of timber 120 Shear 120 Bending 120 Deflection 121 Chapter 7 Foundations 123 Purpose of foundations 123 The history of foundations 123 Building Regulation requirements 124 Stepped foundation 125 Types of foundation 126 Piles 132 Bearing pressure 134 Bearing capacity 134 Eccentric loading on foundations 137 Climatic and moisture changes 138 Physical damage by trees 139 Underpinning 139 Chapter 8 Walls 141 The strength of walls 141 Masonry unit 141 Frost resistance and soluble salts 142 Concrete blocks 143 Mortar 143 Lime putty (non-hydraulic lime) 144 Hydraulic lime 144 Important rules in the use of lime mortars 144 Cement 145 Characteristic strength of masonry 145 Slenderness ratio 146 Flexural stiffness and the second moment of area 147 Euler load 148 Leaning walls and stability 153 Movement joints 153 Changes due to temperature changes 154 Changes due to moisture changes 154 Traditional design of walls 155 Middle-third rule 156 Timber frame walls and raking 157 Chapter 9 Floors 161 The history of floors 161 Modern solid floors 162 Suspended floors and engineered floor joists 163 Holes and notches in floor joists 163 Limecrete 168 The use of plaster and lime ash floors 168 Beam and block suspended floors and hollow core floors 171 Damp 171 Salts 172 Sulphate attack 172 Ceilings 173 Chapter 10 Roofs 175 Trussed and cut roofs 175 Modern truss roofs 175 Cut roofs 177 Roof components 179 Wind bracing 188 Roof spread 189 Overloading of roof members 191 Alterations to roof structures 192 Traditional timber frame building trusses 192 Modern rafter design 193 Flat roof construction 195 Chapter 11 Arches and Columns 197 The history of arches 197 Inversion theory 197 Line of thrust 199 Formation of hinges 201 Visible line of thrust 201 Height and thickness of an arch 203 Gothic arch 203 Domes 203 Columns 204 Chapter 12 Geology 209 The importance of understanding geology 209 Sinkholes 209 Landslips 213 Mining 216 Loess 220 Quick sand 220 Seismic activity 220 Drainage and the water table 220 Chapter 13 Site Investigation 223 Site investigation 223 Boreholes 223 Trenches 223 Geophysics 223 Gravity surveys 223 Magnetic surveys 224 Electromagnetic surveys 224 Electrical surveys 224 Ground-penetrating radar 224 Seismic reflection surveys 224 Seismic refraction 224 Made-up ground or fill 225 Walkover 225 Japanese knotweed 227 Buddleia 227 Desk study 227 Radon 228 Chapter 14 Stability of Buildings 229 Disproportionate collapse 229 Class 1 230 Class 2A 230 Class 2B 230 Class 3 231 Chapter 15 Dimensions of Buildings 233 Building Regulations Part A 233 Slenderness ratio 234 Buttresses and end restraints 245 Lateral restraint of walls and roofs 245 Chapter 16 Basements and Retaining Structures 247 Structural considerations 247 Safety factors 248 Theory behind the design 248 Loading 248 Angle of shearing resistance 250 Effects of water 251 Proportions of walls 251 Design example 252 Specialist advice 260 Types of wall 278 Basements 281 Chapter 17 Structural Alterations 283 Preliminary considerations 283 Removal of walls 283 Alterations to timbers and trusses 285 Alterations to roof structures for dormers 287 Loft conversions 288 Flitch beams 289 Lintels and openings 293 Chapter 18 Structural Defects in Buildings 295 Structural defects 295 Compression 295 Tension 295 Shear 295 Random cracking 295 Location of cracking 296 Roof spread 296 Settlement 296 Shrinkage due to thermal and moisture movements 297 Movement of brickwork along the damp-proof course 298 Subsidence 298 Chemical reactions 301 High alumina cement (HAC) 302 Wall tie failure 302 Damp 303 Overloading 303 Professional advice 305 Chapter 19 The Ancient Use of Sign and Geometry in the Setting Out of Buildings 307 Daisy wheel 307 The golden number or golden mean 307 Pythagoras 309 Masonic markings 309 Ordnance datum bench marks 310 References 313 Index 315