Contents
Declaration i
Approval Certificate iii
Acknowledgement v
Abstract vii
List of Tables xi
List of Figures xiii
CHAPTER 1 INTRODUCTION 1
1.1 Code Clauses for Irregularities 2
1.1.1 Re-entrant corner 2
1.1.2 Torsional irregularity 4
1.2 Necessity for the study 4
1.3 Objective of Study 5
CHAPTER 2 LITERATURE STUDY 6
CHAPTER 3 STRUCTURAL MODELLING 11
3.1 General 11
3.2 Analysis Using ETABS 11
3.3 Modelling of building frames in ETABS 11
3.3.1 Building Model Description 11
3.3.2 Geometry of the building & Seismic Data to be considered in Model 12
CHAPTER 4 METHOD OF ANALYSIS 15
4.1 Overview of seismic methods 15
4.1.1 Equivalent Static Method 15
4.1.2 Dynamic Analysis Method 17
CHAPTER 5 CASE STUDIES 19
5.1 Centre of mass and centre of resistance 20
5.2 Storey Displacement 23
5.3 Model Mass Participation 26
5.4 Mode Shapes 27
5.5 Proposed Location and sizes of column to mitigate torsion 31
5.5.1 For 18-meter height building 31
5.5.2 For 33-meter height building 31
5.5.3 For 48-meter height building 32
CHAPTER 6 DISCUSSION ON RESULTS 34
6.1 Comparison of earthquake forces by changing Aspect Ratio 35
6.2 Normalized Shear Force 37
6.2.1 Corner column C1 37
6.2.2 Edge Column C10 and C19 38
6.2.3 Intermediate Column C9 & C20 40
6.2.4 Re-entrant Column C8 41
6.3 Normalized Design Bending Moment 42
6.3.1 Corner Column C1 42
6.3.2 Edge Column C10 and C19 44
6.3.3 Intermediate Column C9 & C200 45
6.3.4 Re-entrant Column C8 46
6.4 Conclusion 49
CHAPTER 7 REFERENCES 51