Modeling and effects of structural pounding of adjacent structures during seismic events.

by

ACKNOWLEDGEMENT

I would take this opportunity to thank my research supervisor, family and friends for their support and guidance without which this research would not have been possible

DECLARATION

I, [type your full first names and surname here], declare that the contents of this dissertation/thesis represent my own unaided work, and that the dissertation/thesis has not previously been submitted for academic examination towards any qualification. Furthermore, it represents my own opinions and not necessarily those of the University (Bardhan, 2001, 467).

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ABSTRACT

Pounding between adjacent structures is commonly observed phenomenon during earthquakes. In metropolitan areas, due to increasing population and land values buildings have been constructed very close to each other. Although seismic pounding between adjacent structures is considered in codal provisions, the practice of construction is still a problem in developing countries resulting more vulnerable during earthquakes.

To study the effect of structural pounding, a case study has been done on different setbacks and storey heights of two adjacent structures using SAP 2000. The pounding responses of two structures and collision forces are calculated. The effect of collision is more when structures are kept at extreme levels of setback. When the structures are kept at different elevation levels (setback=0), the pounding response changes significantly as the height of structure decreases.

TABLE OF CONTENTS

CHAPTER 1: INTRODUCTION1

1.1 Background of the Study4

1.2 Past research studies on poundings6

CHAPTER 2: LITERATURE REVIEW9

2.1 Seismic Pounding Effect between Buildings13

CHAPTER 3: METHODOLOGY15

3.1 Modeling Of Structures15

3.2 Mathematical Formulation16

3.3 Gap Element Model17

3.4 Pounding Models19

3.4.1 Elastoplastic impact element19

3.4.2 Nonlinear viscoelastic impact element20

3.4.3 Viscous elastoplastic impact element22

CHAPTER 4: ANALYSIS24

4.1 Numerical Investigation24

4.2 Non-Linear Analysis Of Pounding27

4.3 Case-I: Different Setback27

4.3.1 At Setback of 1.5 m27

4.3.2 At Setback f 3.0m29

4.3.3 At Setback of 6.0 m30

4.4 Case-I: Different Setback31

4.4.1 At (3/4)th Height of Structure31

4.4.2 At (2/4)th Height of Structure32

CHAPTER 5: CONCLUSION35

5.1 Setback Level35

5.2 Height Level35

REFERENCES37

CHAPTER 1: INTRODUCTION

Earthquakes are natural disasters of a generally unpredictable nature. In spite of considerable efforts made towards improving the understanding of these natural disasters and protecting built environment from their effects, earthquakes still cause huge human and economic losses; this is true both for highly industrialized and lesser developed countries. Recent examples of earthquakes which caused significant economic losses are the 1994 Northridge (California) earthquake which killed 57 people and caused the economic loss of approximately $40 billion, and the 1995 Great Hanshin (Kobe, Japan) earthquake that killed more than 5,000 people and caused the economic loss of $110 billion. Some other recent earthquakes caused smaller economic losses, however these events caused a significantly larger number of fatalities, e.g. the recent 1999 Izmit (Turkey) earthquake caused 15,000 deaths and the 1993 Killari (India) earthquake caused 10,000 deaths. Also, September 1999 Chi-Chi (Taiwan) earthquake caused over 2,400 deaths and the economic loss of over $30 billions. Most of the human and economic losses in these earthquakes were due to the collapse of buildings and other man-made structures [18].

An earthquake is the result from the sudden release of stored energy in the Earth's crust that creates ...