WATER AS ENERGY ABSORBER TO CONTROL THE SEISMIC RESPONSE OF THE STRUCTURES PDF

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WATER AS ENERGY ABSORBER TO CONTROL THE SEISMIC RESPONSE OF THE STRUCTURES A THESIS SUBMITTED TO THE UNIVERSITY OF MUMBAI FOR THE Ph.D. (Tech.) Degree in CIVIL ENGINEERING SUBMITTED BY NISHANT KISHORE RAI UNDER THE GUIDANCE OF PROF. G. R. REDDY TEACHER OF MUMBAI UNIVERSITY FOR Ph. D. HEAD, STRUCTURA...

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WATER AS ENERGY ABSORBER TO CONTROL THE SEISMIC RESPONSE OF THE STRUCTURES Nishant Rai

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WATER AS ENERGY ABSORBER TO CONTROL THE SEISMIC RESPONSE OF THE STRUCTURES

A THESIS SUBMITTED TO THE

UNIVERSITY OF MUMBAI FOR THE Ph.D. (Tech.) Degree in

CIVIL ENGINEERING

SUBMITTED BY NISHANT KISHORE RAI

UNDER THE GUIDANCE OF PROF. G. R. REDDY TEACHER OF MUMBAI UNIVERSITY FOR Ph. D. HEAD, STRUCTURAL AND SEISMIC ENGINEERING SECTION REACTOR SAFETY DIVISION BHABHA ATOMIC RESEARCH CENTRE MUMBAI- 400078

June 2013

i

Thesis

| Water as energy absorber to control the seismic response of the structure

Water as Energy Absorber to Control the Seismic Response of the Structures

A Thesis Submitted to the University of Mumbai for the Ph.D. (Tech.) Degree in Civil Engineering Submitted by Nishant Kishore Rai

Under the guidance of Prof. G. R. Reddy Teacher of Mumbai University for Ph. D. Head, Structural and Seismic Engineering Section Reactor Safety Division Bhabha Atomic Research Centre Mumbai, 400078

June 2013 ii

Thesis

| Water as energy absorber to control the seismic response of the structure

STATEMENT BY THE CANDIDATE As required by the University Ordinance 770, I wish to state that the work embodied in this thesis titled “Water as Energy Absorber to Control the Seismic Response of the Structures” forms my own contribution to the research work carried out under the guidance of Prof. G.R. Reddy at Bhabha Atomic Research Centre, Mumbai. This work has not been submitted for any other degree of this or any other University. Whenever reference has been made to previous works of others, it has been clearly indicated as such and included in the Bibliography.

(Nishant Kishore Rai) Research Student

Certified By

_______________ Prof. G.R. Reddy Research Guide for Ph.D. (Mumbai University) Head, Structural and Seismic Engineering Section Reactor Safety Division, Bhabha Atomic Research Centre, Mumbai-400085

iii

Thesis

| Water as energy absorber to control the seismic response of the structure

DEDICATION

To my mother in heaven

iv

Thesis

| Water as energy absorber to control the seismic response of the structure

Acknowledgements

I would like to thank my guide, Professor G. R. Reddy, for introducing and guiding me through the fruitful area of seismic retrofitting. Professor G. R. Reddy has allowed me to expand my areas of professional interest far beyond my original intentions and expectations. His continuous encouragement, support and guidance have resulted in the accomplishment of this research in the field of seismic retrofitting of medium height structure with tuned sloshing water dampers. I would like to express my sincere appreciations to my Ph.D. defense committee members, for their valuable time, helpful discussions and useful suggestions. I would like to thank Directorate of Construction Services and Estate management, Department of Atomic Energy as a whole for its support in performing my research work. I would like to thank my all seniors and colleagues for supporting me to pursue this work. Next, I would like to thank Dr. S. J. Patil, a fellow PhD student, for his friendship and tremendous support during the course of this study. Special mention of my gratitude to Mr. N.S. Gabhane, Mr. V. Venkatraj and Mr. P. Aggarwal of DCSEM and Dr. A. P. Tiwari, of BARC, for their encouraging inputs during the tough phases of this study. Many thanks go to my friends Mr. S. K. Bhise and Mr. S. K. Saini at Directorate of Construction Services and Estate management. A special word of thanks goes to Mr. P.N. Dubey of RSD, BARC, for his continuous support and regular hardware inputs in the course of this research. Finally, I would like to extend my profound and deep hearted appreciation and love for my father, wife and children for their much needed, fun punched, support for this research.

Nishant Kishore Rai

v

Thesis

| Water as energy absorber to control the seismic response of the structure

Table of Contents

Title

i

Statutory declarations

ii

Statement by the candidate

iii

Dedication

iv

Acknowledgement

v

Table of contents

vi

List of figures

xi

List of tables

xvii

List of abbreviations

xix

list of symbols

xx

Abstract

xxii

Chapter1

Introduction to Seismic Retrofitting Concepts and Response Control Systems

1 to 26

1.1

Factors governing the engineering of seismic retrofitting

2

1.2

Conventional seismic retrofitting methods

4

1.2.1 Mass reduction

4

1.2.2 Strengthening of existing structural members

4

1.2.3 Addition of structural members

6

1.3

Isolation systems

6

1.4

Supplementary damping systems

9

1.4.1 Passive response control systems

10

1.4.2 Active response control systems

11

1.4.3 Semi-active response control systems

12

1.4.4 Hybrid response control systems

13

1.4.5 Challenges associated with Active, semi-active and hybrid systems Brief description of passive energy dissipating devices

14

1.5.1 Metallic yield dampers

16

1.5.2 Friction dampers

17

1.5.3 Viscoelastic dampers

18

1.5.4 Viscous fluid dampers (VFD)

19

1.5

vi

Thesis

| Water as energy absorber to control the seismic response of the structure

15

1.5.5 Tuned mass dampers

19

1.5.6 Tuned liquid dampers

20

1. 6

24

Organization of the thesis

Chapter 2

Literature Review on Passive Response Control with Tuned Sloshing Water Dampers

2.1

Evolution of tuned liquid dampers

26 to 62

26

2.1.1 Tuned sloshing water damper

27

2.1.2 Tuned liquid column dampers

28

2.1.3 TLCDs and TSWDs installed on civil engineering structures

28

2.2

Theoretical Studies on TSWDs

31

2.2.1 Numerical modelling of tuned sloshing water dampers

31

2.2.2 Equivalent mechanical model (without damping)

36

2.2.3 Equivalent mechanical model with damping

38

2.2.4 Studies on non-linear sloshing

39

2.3

Experimental studies on TSWD

41

2.4

Studies on modified TSWD configurations

43

2.5

Study on TSWDs for supressing vertical excitations

45

2.6

Analogical equivalence between TSWD and TMD

45

2.6.1 Tuned mass dampers: introductory concept

46

Equivalent TMD models of TSWD

48

2.7

2.7.1 Kareem model (1987)

48

2.7.2 Sun Model (1995)

49

2.7.3 Yu model (1999)

51

2.7.4 Yalla model (2001)

54

2.7.5 Tait model (2004)

54

2.7.6 Structure-TSWD interaction

56

2.8

Multiple mass damper concept applied to TSWDs

58

2.8.1 Analytical approach for Multiple TSWDs

60

2.8.2 Mass ratio distribution systems for MTSWDs

62

Chapter 3

Retrofitting of Existing Structure with Tuned Sloshing Water Damper

3.1

State of RC framed Existing structures vii

Thesis

63 to96

| Water as energy absorber to control the seismic response of the structure

63

3.2

65

3.3

Seismic behaviour reinforced concrete frame structures with masonry infill Existing structures for the present study

3.4

Details of Structure

68

67

3.4.1 Damping ratio of ES

69

3.4.2 RC frame details

70

3.4.3 Masonry details

71

3.5

Structural Analysis

73

3.6

Discussion on Analytical Results

74

3.7

Retrofitting Strategy

76

3.8

3.7.1 TSWD system subjected to resonant harmonic frequency vibration

77

3.7.2 Optimal TSWD system subjected to non-resonant harmonic frequency vibration Design of retrofitting system with single frequency TSWD (STSWD) 3.8.1 Design of retrofitting system for mean frequency of 1.48 Hz

78

3.8.2 Design of retrofitting system for frequency of 1.766 Hz (Case 4)

83

3.8.3 Design of retrofitting system for frequency of 1.195 Hz (Case 7)

84

3.8.4 Discussions on design proposals

85

3.9

79 81

Design of retrofitting system with multiple frequency TSWD (MTSWD) Effectiveness ratio of a TSWD retrofitting system

3.10

85 87

3.10.1 Detuning of TSWDS

87

3.11

Effective damping ratio of ES with optimal TSWD subjected to resonant harmonic excitation 3.11.1 Design of TSWD retrofitting system based on BIS:1893 and effectiveness coefficient 3.12 Performance charts for TSWDS

88 89 90

3.12.1 Design of TSWD retrofitting system by effectiveness charts

93

3.12.2 Performance Check of MTSWD retrofitting system

95

Chapter 4

Simulated Experimental Studies with TSWD

97 to135

4.1

Scaled model (SM) of existing structure and TSWD

99

4.2

Similitude requirements of ES and SM

99

4.2.1 Linear scaling

99

4.2.2 Material scaling

100

4.2.3 Scaling of cross sectional area of structural member

100

4.2.4 Mass scaling

101

viii

Thesis

| Water as energy absorber to control the seismic response of the structure

4.2.5 Scaling of dynamic properties

101

4.2.6 Excitation and displacement response scaling

101

4.3

Similitude requirements of TSWD

102

4.4

Similitude requirements of retrofitted ES and SM-TSWD coupling

102

4.5

Scaled model, TSWD and laboratory test setup

102

4.6

Test programme

104

4.7

Free vibration tests

105

4.7.1 Verification and behavioural evaluation of structural model (SM)

105

4.7.2 Optimum parameters of TSWD with respect to SM (size search)

106

4.8

4.9

4.10

Forced vibration tests: Harmonic excitations

109

4.8.1 SM subjected to harmonic base excitations (Bare SM tests)

109

4.8.2 SM coupled with optimal TSWDs subjected to harmonic excitations SM coupled with optimal TSWD subjected to ground motion time histories 4.9.1 SM4-TSWD235x80 coupling

109

4.9.2 SM5-TSWD280x80 coupling

116

4.9.3 SM6-TSWD360x80 coupling

118

SM coupled with multiple frequency TSWDs subjected to dynamic excitations 4.10.1 SM-STSWD and SM-MTSWD couplings subjected to forced vibration 4.10.2 SM4 coupled with STSWD and MTSWD systems

121

4.10.3 SM5 coupled with STSWD and MTSWD systems

125

4.10.4 SM6 coupled with STSWD and MTSWD systems

127

4.11

113 114

122 123

SM and TSWD parameters along axis X

128

4.11.1 Free vibration tests

128

4.11.2 Forced vibration tests

130

4.12

SMs coupled with large size TSWDs

132

4.12.1 SM4-TSWD160 coupling

132

4.12.2 SM5-TSWD160 coupling

133

4.13

Inferences from experimental observations

Chapter 5

Effectiveness of TSWD Retrofitting System for Dynamic Response Reduction

5.1

Testing Protocol ix

Thesis

135 136 to179

136 | Water as energy absorber to control the seismic response of the structure

5.2

Free vibration tests

138

5.2.1

First mode frequencies of SMs

138

5.2.2

Determination of optimum TSWD parameters (size search)

140

Forced vibration tests: Harmonic excitations

144

5.3.1

Bare SM subjected to resonant harmonic

144

5.3.2

144

5.4

Optimised SM-TSWD couplings subjected to resonant frequency harmonic excitations Forced vibration tests: Broad band earthquake excitations

5.5

Multiple frequency TSWD (MTSWD) system

150

5.5.1

Test protocol

151

5.5.2

SMs subjected to dynamic excitations in coupling with STSWD and MTSWD systems TSWD parameters along axis X

152

5.6.1

Size search with respect to SM

154

5.6.2

Forced vibration tests

154

Test with large size TSWDs

155

5.7.1

Size search

155

5.7.2

Forced vibration test

156

5.8

Inferences from experimental observations

157

5.9

161

5.9.3

Design of TSWD retrofitting system based on experimental investigations Designing the MTSWD system for desired response reduction of SM Designing the MTSWD system for desired response reduction of ES Execution scheme

5.9.4

Discussion on design of TSWD retrofitting system

177

5.9.5

Retrofitting design methodology with TSWD systems

177

5.3

5.6

5.7

5.9.1 5.9.2

148

154

162 174 175

Chapter 6

Conclusions

180 to187

6.1

Summary

180

6.2

Significant inferences from the study

182

6.3

Recommendations Future Research

186

Bibliography

188 to199

Synopsis

200 to229

Visible Research Output

x

Thesis

| Water as energy absorber to control the seismic response of the structure

230

List of Figures Figure 1.1

Response spectrum from BIS 1893-2002

2

Figure 1.2

Effect of damping ratio on structural response (for concrete structures)

3

Figure 1.3

Engineering process of retrofit decision making

3

Figure 1.4

Retrofitting by jacketing of columns and beams

5

Figure 1.5

Retrofitting by carbon fibre wrapping of columns and beams

5

Figure 1.6

6

Figure 1.7

Effect of addition of structural members on the lateral load carrying capacity of the structures Reduced response due to frequency shift through base isolation

Figure 1.8

Commonly used base isolation devices

7

Figure 1.9

Friction pendulum base isolation system

8

Figure 1.10

Fixed base and base isolated subjected to actual earthquakes Guwahati

9

Figure 1.11

Seismic energy absorption in conventional structure

10

Figure 1.12

Structure with passive energy dissipating (PED) device

10

Figure 1.13

Structure with active control system

11

Figure 1.14

Structure with semi-active control systems

12

Figure 1.15

Structure with hybrid control system

13

Figure 1.16

Hybrid control with Duox system

14

Figure 1.17

Metallic yield dampers

16

Figure 1.18

Lead extrusion dampers

17

Figure 1.19

Pal friction damper configuration and execution

18

Figure 1.20

Viscoelastic damper

18

Figure 1.21

Viscous fluid damper

19

Figure 1.22

Taipai 101 with tuned mass damper

20

Figure 1.23

Tuned liquid damper family

21

Figure 1.24

Tuned sloshing water damper on top of the building

21

Figure 1.25

Schematic of a TLCD on a single degree of freedom system

22

Figure 2.1

Interconnected tanks as rolling stabiliser in marine applications

26

Figure 2.2

Buildings / structures with Tuned Liquid Damper installations

29

Figure 2.3

Buildings/ structures with Tuned Liquid Damper installations

30

Figure 2.4

Fundamental anti-symmetric wave (sloshing) in a moving tank

32

xi

Thesis

| Water as energy absorber to control the seismic response of the structure

7

Figure 2.5

Equivalent mechanical models of sloshing

32

Figure 2.6

Coordinate system for the derivation of basic slosh equation

33

Figure 2.7

Definition sketches of slosh wave motion and shapes for a rectangular tank

34

Figure 2.8

Equivalent mechanical models for liquid sloshing in rectangular tank

36

Figure 2.9

Mechanical model of liquid sloshing in rectangular tank with damping