Table Of Content

CIVIL ENGINEERING GUPTA SECOND EDITION Principles of S STRUCTUR AL DESIGN T R Wood, Steel, and Concrete U C “…a valuable source that provides efficient and authoritative guidance for students learning T P the fundamentals of codes and standards in structural material design.” r ––Dr. Peggi L. Clouston, University of Massachusetts, Amherst, USA U i n R c “From design loads determination and building codes, to various design philosophies, i to load distribution and load paths, the student is given a road map for designing a structure p A that answers the common question of ‘where do I begin?’… It is concise and focuses on l e applications rather than extensive theoretical background and current research…” L s ––Caesar Abi Shdid, Ph.D., P.E., Lebanese American University, Beirut, Lebanon o D f E A structural design book with a code-connected focus, Principles of Structural Design: Wood, Steel, and Concrete, Second Edition introduces the principles and practices of structural design. This book S covers the section properties, design values, reference tables, and other design aids required to accomplish I complete structural designs in accordance with the codes. G What’s New in This Edition: N • Reflects all the latest revised codes and standards • The text material has been thoroughly reviewed and expanded, including a new chapter on concrete design • Suitable for combined design coursework in wood, steel, and concrete • Includes all essential material—the section properties, design values, reference tables, and other design aids required to accomplish complete structural designs according to the codes • This book uses the LRFD basis of design for all structures SECOND Principles of Structural Design: Wood, Steel, and Concrete, Second Edition was designed to be used EDITION for joint coursework in wood, steel, and concrete design. K15209 6000 Broken Sound Parkway, NW Suite 300, Boca Raton, FL 33487 711 Third Avenue New York, NY 10017 an informa business 2 Park Square, Milton Park www.crcpress.com Abingdon, Oxon OX14 4RN, UK w w w . c r c p r e s s . c o m K15209_cover.indd 1 3/24/14 12:04 PM SECOND EDITION Principles of STRUCTUR AL DESIGN Wood, Steel, and Concrete SECOND EDITION Principles of STRUCTUR AL DESIGN Wood, Steel, and Concrete RAM S. GUPTA Boca Raton London New York CRC Press is an imprint of the Taylor & Francis Group, an informa business CRC Press Taylor & Francis Group 6000 Broken Sound Parkway NW, Suite 300 Boca Raton, FL 33487-2742 © 2014 by Taylor & Francis Group, LLC CRC Press is an imprint of Taylor & Francis Group, an Informa business No claim to original U.S. Government works Version Date: 20140213 International Standard Book Number-13: 978-1-4665-5233-3 (eBook - PDF) This book contains information obtained from authentic and highly regarded sources. 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Visit the Taylor & Francis Web site at http://www.taylorandfrancis.com and the CRC Press Web site at http://www.crcpress.com Contents Preface............................................................................................................................................xiii Author ..............................................................................................................................................xv Section i Design Loads Chapter 1 Design Criteria .............................................................................................................3 Classification of Buildings ...........................................................................................3 Building Codes .............................................................................................................3 Standard Unit Loads .....................................................................................................3 Tributary Area ..............................................................................................................3 Working Stress Design, Strength Design, and Unified Design of Structures ..............7 Elastic and Plastic Designs .........................................................................................10 Elastic Moment Capacity .......................................................................................12 Plastic Moment Capacity .......................................................................................12 Combinations of Loads ..............................................................................................14 Other Loads ................................................................................................................15 Continuous Load Path for Structural Integrity ..........................................................18 Problems .....................................................................................................................18 Chapter 2 Primary Loads: Dead Loads and Live Loads ............................................................23 Dead Loads.................................................................................................................23 Live Loads ..................................................................................................................24 Floor Live Loads ........................................................................................................24 Basic Design Live Load, L ...................................................................................24 o Effective Area Reduction Factor ...........................................................................24 Other Provisions for Floor Live Loads .......................................................................26 Multiple Floors Reductions ...................................................................................27 Roof Live Loads, L ....................................................................................................28 r Tributary Area Reduction Factor, R .....................................................................28 1 Slope Reduction Factor ..........................................................................................28 Problems .....................................................................................................................29 Chapter 3 Snow Loads ................................................................................................................31 Introduction ................................................................................................................31 Minimum Snow Load for Low-Slope Roofs ..............................................................31 Balanced Snow Load ..................................................................................................34 Importance Factor .................................................................................................34 Thermal Factor, C .................................................................................................34 t Exposure Factor, C ...............................................................................................35 e Roof Slope Factor, C .............................................................................................35 s v vi Contents Rain-on-Snow Surcharge ...........................................................................................36 Partial Loading of the Balanced Snow Load .............................................................37 Unbalanced across the Ridge Snow Load ..................................................................38 Snow Drift from a Higher to a Lower Roof ...............................................................40 Leeward Snow Drift on Lower Roof of Attached Structure .................................40 Windward Snow Drift on Lower Roof of Attached Structure ..............................41 Leeward Snow Drift on Lower Roof of Separated Structure ................................42 Windward Snow Drift on Lower Roof of Separated Structure .............................42 Sliding Snow Load on Lower Roof ............................................................................44 Sliding Snow Load on Separated Structures ..............................................................46 Problems .....................................................................................................................46 Chapter 4 Wind Loads ................................................................................................................49 Introduction ................................................................................................................49 Definition of Terms ....................................................................................................49 Procedures for MWFRS.............................................................................................50 Simplified Procedure for MWFRS for Low-Rise Buildings......................................50 Horizontal Pressure Zones for MWFRS ...............................................................57 Vertical Pressure Zones for MWFRS ...................................................................61 Minimum Pressure for MWFRS ...........................................................................61 Procedures for Components and Cladding.................................................................66 Simplified Procedure for Components and Cladding for Low-Rise Buildings ....................................................................................................66 Minimum Pressures for Components and Cladding .............................................70 Problems .....................................................................................................................72 Chapter 5 Earthquake Loads ......................................................................................................75 Seismic Forces ............................................................................................................75 Seismic Design Procedures ........................................................................................75 Definitions ..................................................................................................................76 Structural Height ...................................................................................................76 Stories above Base and Grade Plane .....................................................................76 Fundamental Period of Structure ..........................................................................77 Ground Motion Response Accelerations ....................................................................77 Mapped MCE Spectral Response Acceleration Parameters ................................78 R Adjustments to Spectral Response Acceleration Parameters for Site Class Effects ..........................................................................................................78 Design Spectral Acceleration Parameters .............................................................78 Design Response Spectrum ...................................................................................78 Importance Factor, I ...................................................................................................88 Seismic Design Categories .........................................................................................88 Exemptions from Seismic Designs .............................................................................90 Equivalent Lateral Force Procedure to Determine Seismic Force.............................90 Effective Weight of Structure, W ...........................................................................90 Seismic Response Coefficient, C ..........................................................................90 s Response Modification Factor or Coefficient, R....................................................91 Distribution of Seismic Forces ...................................................................................92 Distribution of Seismic Forces on Vertical Wall Elements ...................................92 Distribution of Seismic Forces on Horizontal Elements (Diaphragms) .........................................................................................93 Contents vii Design Earthquake Load ............................................................................................94 Soil–Structure Interaction ..........................................................................................98 Problems .....................................................................................................................99 Section ii Wood Structures Chapter 6 Wood Specifications .................................................................................................105 Engineering Properties of Sawn Lumber .................................................................105 Reference Design Values for Sawn Lumber .............................................................105 Adjustments to the Reference Design Values for Sawn Lumber ..............................106 Time Effect Factor, λ ...........................................................................................107 Size Factor, C .....................................................................................................107 F Size Factor, C , for Dimension Lumber ..........................................................108 F Size Factor, C , for Timber .............................................................................108 F Repetitive Member Factor, C ..............................................................................108 r Flat Use Factor, C ..............................................................................................108 fu Buckling Stiffness Factor, C ..............................................................................108 T Bearing Area Factor, C ......................................................................................108 b Format Conversion Factor, K .............................................................................109 F Resistance Factor, ϕ.............................................................................................109 Load Resistance Factor Design with Wood .............................................................109 Structural Glued Laminated Timber ........................................................................114 Reference Design Values for Glued Laminated Timber ..........................................115 Adjustment Factors for Glued Laminated Timber ...................................................116 Flat Use Factor for Glued Laminated Timber, C .............................................116 FU Volume Factor for Glued Laminated Timber, C ................................................116 v Curvature Factor for Glued Laminated Timber, C ............................................116 c Stress Interaction Factor, C .................................................................................118 I Shear Reduction Factor, C ................................................................................118 VR Structural Composite Lumber ..................................................................................120 Summary of Adjustment Factors ..............................................................................121 Problems ...................................................................................................................123 Chapter 7 Flexure and Axially Loaded Wood Structures ........................................................125 Introduction ..............................................................................................................125 Design of Beams ......................................................................................................125 Bending Criteria of Design ......................................................................................125 Beam Stability Factor, C .........................................................................................127 L Effective Unbraced Length ..................................................................................128 Shear Criteria ...........................................................................................................129 Deflection Criteria ....................................................................................................131 Creep Deflection .......................................................................................................132 Bearing at Supports ..................................................................................................136 Bearing Area Factor, C ......................................................................................137 b Design of Axial Tension Members ...........................................................................138 Design of Columns ...................................................................................................140 Column Stability Factor, C .....................................................................................141 P Design for Combined Bending and Compression ....................................................143 Problems ...................................................................................................................147 viii Contents Chapter 8 Wood Connections ...................................................................................................153 Types of Connections and Fasteners ........................................................................153 Dowel-Type Fasteners (Nails, Screws, Bolts, Pins) ..................................................153 Yield Limit Theory for Laterally Loaded Fasteners ................................................154 Yield Mechanisms and Yield Limit Equations ........................................................155 Reference Design Values for Lateral Loads (Shear Connections) ...........................157 Reference Design Values for Withdrawal Loads .....................................................157 Adjustments of the Reference Design Values ..........................................................157 Wet Service Factor, C ........................................................................................158 M Temperature Factor, C ........................................................................................158 t Group Action Factor, C ......................................................................................158 g Geometry Factor, C ............................................................................................158 ∆ End Grain Factor, C ..........................................................................................161 eg Diaphragm Factor, C .........................................................................................161 di Toenail Factor, C ...............................................................................................161 tn Nail and Screw Connections ....................................................................................164 Common, Box, and Sinker Nails .........................................................................164 Post-Frame Ring Shank Nails .............................................................................164 Wood Screws .......................................................................................................165 Bolt and Lag Screw Connections .............................................................................166 Bolts .....................................................................................................................167 Lag Screws ..........................................................................................................167 Problems ...................................................................................................................168 Section iii Steel Structures Chapter 9 Tension Steel Members ............................................................................................175 Properties of Steel ....................................................................................................175 Provisions to Design Steel Structures ......................................................................175 Unified Design Specifications ..................................................................................176 Limit States of Design .........................................................................................176 Design of Tension Members .....................................................................................177 Tensile Strength of Elements ....................................................................................177 Net Area, A .........................................................................................................178 n Effective Net Area, A .........................................................................................179 e Block Shear Strength ................................................................................................182 Design Procedure for Tension Members ..................................................................184 Problems ...................................................................................................................186 Chapter 10 Compression Steel Members ....................................................................................191 Strength of Compression Members or Columns ......................................................191 Local Buckling Criteria ............................................................................................193 Flexural Buckling Criteria .......................................................................................194 Effective Length Factor for Slenderness Ratio ........................................................194 Limit States for Compression Design ......................................................................197 Nonslender Members ................................................................................................197 Flexural Buckling of Nonslender Members in Elastic and Inelastic Regions ..................................................................................................197