TY - BOOK AU - Murty, C.V.R. & Others TI - Some concepts in earthquake behaviour buildings U1 - 624.1762 PY - 2012/// CY - Gujarat PB - Gujarat State Disaster Management Authority N1 - Earthquake resistantBuildings 1.1 Basics of Earthquake-Resistant Design and Construction 1 1.2 Basic Aspects of Seismic Design 2 1.3 The Four Virtues of Earthquake Resistant Buildings 5 1.3.1 Characteristics of Buildings 5 (a) Seismic Structural Configuration 5 (b) Structural Stiffness, Strength and Ductility 8 1.3.2 What are the Four Virtues? 9 (a) Who Controls the Four Virtues? 9 (b) How to Achieve the Four Virtues? 10 1.4 Earthquake Demand versus Earthquake Capacity 10 1.5 Force-based Design to Displacement-based Design 13 Earthquake Demand on Buildings 2.1 Seismic Design Force . 15 2.2 Dynamic Characteristics of Buildings 18 2.2.1 Natural Period 18 (a) Fundamental Natural Period of Building 19 (b) Factors influencing Natural Period 20 (1) Effect of Stiffness 21 (2) Effect of Mass 22 (3) Effect of Building Height 23 (4) Effect of Column Orientation 24 (5) Effect of Unreinforced Masonry Infill Walls in RC Frames 24 (6) Effect of Cracked Sections on Analysis of RC Frames 25 (c) Design Practice 27 2.2.2 Mode Shape 29 (a) Fundamental Mode Shape of Oscillation 29 (b) Factors influencing Mode Shapes 32 (1) Effect of Flexural Stiffness of Structural Elements 32 (2) Effect of Axial Stiffness of Vertical Members 34 (3) Effect of Degree of Fixity at Member Ends 36 (4) Effect of Building Height 38 (5) Effect of Unreinforced Masonry Infill Walls in RC Frames 40 (c) Design Practice 44 2.2.3 Damping 45 2.3 Ground Motion Characteristics - 47 2.3.1 Accelerograms 47 2.3.2 Response Spectrum of a Ground Motion 49 (a) Acceleration Response Spectrum of a Ground Motion 51 (b) Design Practice 52 of Buildings - Elastic Behaviour 3.1 Elastic Behaviour 53 3.2 Configuration 53 3.2.1 Overall Geometry 53 (a) Plan Shape 53 (1) Buildings with different shapes, but same Plan Area 54 (2) Buildings with different projections, but same Plan Shape 64 (b) Plan Aspect Ratio 71 (1) Buildings with distributed LLRS in plan and cut-outs 74 (2) Buildings with regular plan shape, but of large plan size and with cut-outs 74 (c) Slenderness Ratio 81 3.2.2 Structural Systems and Components 83 (a) Moment Frame Systems 84 (b) Structural Wall-Frame Systems 94 (c) Braced Frame Systems 99 (d) Tube System 103 (e) Tube-in-Tube and Bundled Tube Systems 109 (f) Flat Slab Building 117 3.2.3 Load Paths 127 (a) Frames 124 (b) Structural Walls 128 3.3 Mass 134 3.3.1 Mass Asymmetry in Plan 134 3.3.2 Mass Irregularity in Elevation 135 3.4 Initial Stiffness 137 3.4.1 Stiffness Irregularity in Plan 137 3.4.2 Stiffness Irregularity in Elevation 143 (a) Open or Flexible Storey in Buildings 143 (b) Plinth and Lintel Beams in Buildings 147 (c) Buildings on Slope 151 (d) Set-back and Step-back Buildings 151 3.4.3 Adjacency 161 3.4.4 Soil Flexibility 16 Earthquake Capacity of Buildings.-. Inelastic Behaviour 4.1 Inelastic Behaviour 173 4.2 Strength 173 4.2.1 Strength Hierarchy 174 (a) Beam-Column Joints 180 4.2.2 Structural Plan Density 183 4.2.3 Strength Asymmetry in Plan 186 4.2.4 Strength Discontinuity in Elevation 190 (a) Open/ Flexible/ Weak Storeys in a Building 192 (b) Discontinuous Structural Walls in a Building 196 (c) Short Column Effect 200 4.3 Ductility 205 . 4.3.1 Definitions of Ductility 205 (a) Contributors to Ductility in Reinforced Concrete Buildings 205 (b) Achieving Ductility in Reinforced Concrete Buildings 216 (c) Assessing Ductility available in Buildings 216 4.3.2 Strength Provided in Building and Overall Ductility Demand 220 4-3-3 Capacity Design of Buildings 222 (a) Displacement Loading 222 (b) Capacity Design Concept 224 4.3.4 Distribution of Damage in Building 227 (a) The Open Ground Storey Buildings 228 (b) Strong Column - Weak Beam Design 232 (c) Excessive ductility demands owing to Pounding from Adjacent Building 237 Adjacent Part of same Building 4.4 Modeling of Buildings 238 5 Earthquake-Resistant Design of Buildings 5.1 Introduction 241 5.2 Earthquake-Resistant Design Methods 245 5.3 Earthquake-Resistant Design Procedure 247 5.3.1 Stiffness Design Stage 247 5.3.2 Strength Design Stage 249 5.3.3 Ductility Design Stage 250 5.4 Closing Comments 250 ER -