Contents
Foreword
Preface iv
Acknowledgements vi
Table of contents
1. Earthquakes and How They Affect Buildings 1
1.1 The Nature of Earthquakes 1
1.2 How Earthquake Forces Develop 4
1.3 How Earthquake Forces are Resisted by the Building Components 8
1.4 Prerequisites for Satisfactory Earthquake Performance of Buildings 10
2. Confined Masonry: Key Components and Worldwide Applications 15
2.1 Key Components 15
2.2 Worldwide Applications 18
2.3 Confined Masonry Construction in India 30
3. How are Confined Masonry Buildings Different from Unreinforced Masonry and RC Frames with Masonry lnfills? 39
3.1 Background 39
3.2 CM vs URM Buildings 39
3.3 CM vs RC Frames with masonry infills 40
4. How Earthquake Forces are Resisted in Confined Masonry Buildings 47
4.1 Background 47
4.2 How Seismic Forces are Resisted by Confined Masonry Walls 47
4.3 Failure Mechanisms 49
4.4 Modelling CM Walls for Seismic Analysis 52
5. How Confined Masonry Buildings Performed in Past Earthquakes 57
5.1 Introduction 57
5.2 Key Factors 57
5.3 Performance of CM buildings in Past Earthquakes 64
5.4 Earthquake Simulation Testing 68
6. Conceptual Architectural Planning and Design of Confined Masonry Buildings 73
6.1 Background 73
6.2 Building Configuration (BC) 74
6.3 Wall Layout 79
6.4 Confining Elements in CM Walls 81
6.5 Openings in CM Walls 85
7. Preliminary Seismic Safety Check for CM Buildings 89
7.1 Background 89
7.2 What is Wall Index? 89
7.3 When can the Wall Index be used for a Seismic Safety Check? 90
7.4 How to Estimate the Required Wall Index for a CM Building in India? 92
7.5 Design Case Study 1: Seismic Safety Check for a G+1 Bungalow in
Seismic Zone V of India 94
7.6 Design Case Study 2: RC Building Modified into a CM Building inSeismic Zone Ill of India 99
7.7 Further Readings 104
8. Construction of CM Buildings 105
8.1 Background 105
8.2 Building Materials and Construction Practice 105
8.3 Foundation and Plinth 105
8.4 RC Tie-Columns 106
8.5 Masonry Walls 108
8.6 RC Lintel Bands 112
8.7 RC Tie-Beams and Floor Slabs 113
8.8 Further Reading 116
9. Conc luding Remarks 119
References 121
Appendix A Sample Construction Specification for Confined Masonry 131