Chapter 1: iniroduction
1.1 Non-structural Elements 1
1.1.1 Distinction between Structural and Non-structural Elements 2
1.2 Classification of Non-structural Elements 5
1.2.1 Mistaken as Non-structural Elements 6
(a) Unreinforced Masonry Infill Walls 6
(b) Rooftop Water Tanks 9
(c) Elevator Shaft Core made of RC 9
(d) Staircase Waist Slab and Beams 11
1.3 Performance of Non-structural Elements during Past Earthquakes 12
1.3.1 Damages 12
1.3.2 Importance of Securing NSEs 16
1.4 Major Concerns 20
2.1 The Two Challenges 23
2.2The Protection Strategies 26
2.2.1 Force-Sensitive NSEs 27
(a) NSEs anchored only to Horizontal SEs 27
(b) NSEs anchored only to Vertical SEs 27
(c) NSEs anchored to both Horizontal and Vertical SEs 28
2.2.2 Displacement-Sensitive NSEs
(a) NSEs supported on two SEs on the same Building, but at Different Elevation28
(b) NSE Supported on two SEs that shake independently30
(c) NSE supported on a SE on Building and the Ground 31
2.3 Interaction between SEs and NSEs 31
Chapter 3: Behaviour of NSEs in Earthquake
3.1Effects of Earthquake Shaking on Buildings 33
3.1.1 Floor Acceleration Response 35
(a)Concept 35
(b) Obtaining Floor Acceleration Response 36
(c) Factors Influencing Floor acceleration Response 36
(d) Amplification Factors of Floor Accelerations at Different Floors 38
3.1.2 Displacement Response 39
(a) Concept 39
(b) Obtaining Displacement Response and Inter-storey Drift39
(c) Factors Influencing Displacement Response and Inter-Storey Drifts 40
3.2 Effects of Earthquake Shaking on NSEs 41
3.2.1 Acceleration Effects 41
3.2.2 Displacement Effects
3.3 Behaviour of Unanchored Force Sensitive NSEs 45
3.3.1 Behaviour of Single Block 45
(a) Sliding Only 46
(b) Rocking Only 46
(c) Toppling Only 47
3.3.2 Behaviour of TWO Stacked Blocks 48
(a) Initiation of Motion 49
(b) Equation of Motion 49
3.4 Behaviour of Anchored Force-Sensitive NSEs 51
3.5Behaviour of Displacement-Sensitive NSEs 54
3.5.1 NSEs having Relative Displacement with respect to Ground 54
3.5.2 NSEs having Inter-Storey Relative Displacement 56
3.5.3 NSEs having Relative Displacement between Two Items Shaking Independently 56
3.6 Earthquake Performance of NSEs 58
Chapter 4: Performance Expectation from NSEs during Earthquake
4.1 Earthquake Design Philosophy 61
4.1.1 Expected Levels of Performance 63
4.1.2 Levels of Shaking to be considered 68
4.1.3 Safety from Primary and Secondary Hazards 69
4.2 Broad Suggestions for Architects and Engineers 69
4.2.1 Strategies to Protect Force-Sensitive NSEs 71
4.2.2 Strategies to Protect Displacement-Sensitive NSEs 73
4.3Classification of Protection Strategies 76
(a) Non-Engineered Practice (Common Sense) 76
(b) Pre-Engineered Practice (Prescriptive Approach) 77
(c) Engineered Design Practice (With Calculation) 77
Chapter 5: International Code Provisions for Seismic Protection of NSEs
5.1 Basic Provisions for "Engineered Strategy" of Securing NSEs 79
5.1.1 Development of Code Provisions for NSEs 80
(a) Design Lateral Force for NSEs 82
(b) Design Relative Displacement for NSEs 83
5.1.2 IITK-GSDMA Guidelines for Force Design 85
(a) Design Lateral Force for SEs 87
(b) Design Lateral Force for NSEs 88
5.1.3 IITK-GSDMA Guidelines for Displacement Design 91
(a) Design Relative Lateral Displacement for SEs 91
(b) Design Relative Lateral Displacement for NSEs 91
5.2 Earthquake Performance of Code-Designed Connections of NSEs 93
5.3 Limitations in Current Design Procedure 94
5.4 Uncertainties in Understanding Earthquake Behaviour of NSEs 94
5.4.1 Design Lateral Forces for NSEs 94
(a) Design Peak Ground Acceleration Z . 95
(b) Soil Type & Stratum at the Building Site 95
(c) Floor Acceleration and Displacement along Building Height 95
(d) Response Amplification Factor ap of NSE 98
(e) Response Reduction Factor Rp of NSE 99
(f) Component Importance Factor lp of NSE 100
(g) Seismic Weight Wp of NSE 100
(h) Connection of NSEs to SEs100
(i) Determining the Factors ap Rp and /p100
(j) Type of NSE 5.4.2 Design Relative Displacement for NSEs
(a) Higher Mode of Oscillation
(b) Relative Flexure Stiffness of Beams and Columns
(c) Axial Stiffness of Columns
(d) Inelastic Action in Buildings
(e) Building Irregularities
(f) Soil-Structure Interaction
(g) Connection between NSEs and Building Limitation of Analysis Method
Importance of Capturing Nonlinear Behaviour of Building in Design of NSEs Research Needed
Importance of Seismic Pre-Qualification of NSEs
Chapter 6: Looking Back to Look Ahead
6.1 Summary 109
6.2 Closing Comments 111
Reference
Appendix
Appendix A Appendix B