Seismic Vulnerability of Historical Arch Type Bridge Structures in Italy

68 Pages·2009·5.72 MB·English

Abdul Qadir Bhatti

Seismic Vulnerability of Historical Arch Type
Bridge Structures in Italy
Abdul Qadir Bhatti

Seismic Vulnerability of Historical Arch Type Bridge
Structures in Italy

Supervisor

Francesca Da Porto

This Masters Course has been funded with support
from the European Commission. This publication
reflects the views only of the author, and the
Commission cannot be held responsible for any use
which may be made of the information contained there
in.
Italy 2009

DECLARATION

Name: Abdul Qadir Bhatti
Email: [email protected]

Title of the Seismic Vulnerability of Historical Arch Type Bridge Structures in Italy
Msc Dissertation:
Supervisor(s): Francesca Da Porto
Year: 2009

I hereby declare that all information in this document has been obtained and presented in accordance
with academic rules and ethical conduct. I also declare that, as required by these rules and conduct, I
have fully cited and referenced all material and results that are not original to this work.

I hereby declare that the MSc Consortium responsible for the Advanced Masters in Structural Analysis
of Monuments and Historical Constructions is allowed to store and make available electronically the
present MSc Dissertation.

University: Padova
Date: 20/07/2009
Signature:
___________________________

ACKNOWLEDGEMENTS

I would like to acknowledge the support I got from my supervisor Francesca da Porto who gave
me the opportunity to work in this incredibly historical bridge in a very interesting way.

I would like to express my gratitude to the Msc Consortium and the Erasmus Mundus
Programme for the opportunity to participate in this Master and the financial support.

Last but not least, I would like to sincerely thank to all the friends I made in Padova and
Barcelona for all the moments we shared.

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ABSTRACT

Italy is located on a earthquake prone area and old bridges were desinged without any seismic
provision. In the years (2009), tremors were felt in Italy due to the strong earthquakes at
Abruzzo, which highlight the earthquake threat to Italy.
This study focuses on seismic vulnerability of arch type masonry bridge structures in Italy,
designed primarily for gravity loads, when they are subjected to earthquakes. A case study has
been carried out for the vulnerability study for a 11 m span masonry arch bridge representing
typical bridge structure in Italy. In the case study, nonlinear dynamic analyses for the full scale
structures are carried out. The evaluation of the seismic vulnerability is carried out by
verification of arch at mid span and near support of the bridge. The demand curve is obtained
based on the accelerograms due to the worst earthquake scenario in Italy. From these studies,
it is concluded that the arch type masonry bridges in Italy may suffer some damage due to the
worst possible earthquake.

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LIST OF FIGURES
Pages
Fig. 2.1 Section plan of Masonry bridge 3
Fig. 2.2 Identification of the different parts constituting a masonry arch bridge 4
[Galasco et al., 2004]
Fig. 2.3 Example of Bridge 4
Fig. 2.4 Bridge View from the sea 8
Fig. 2.5 Damage of bridge due to Oct 8, Kashmir earthquake, Pakistan 8
Fig. 2.6 Overturing of the walls for a transport masonry bridge, after the Bhuj 9
earthquake, 2001, India [Gisdevelopment, 2001]
Fig. 2.7. Damage of a masonry bridge, after the Umbria-Marche earthquake, 1997 9
[Resemini and Lagomarsino, 2004]
Fig. 2.8 Location of Bridge 11
Fig. 2.9. Front View of the historical bridge 11
Fig. 2.10. Front View of the Arch of historical bridge 12
Fig. 2.11. Top View of the historical bridge 12
Fig. 2.12. Another View of the Arch of historical bridge 12
Fig. 2.13 Front View of the Arch 12
Fig. 2.14. Enlarge View of the Arch of historical bridge 13
Fig. 3.1 Seismic Classification of Italian Territory 15
Fig.3.2 Seismic map of Italy with three zones 16
Fig.3.3 Seismic map of Italy with Four Zones 17
Fig.3.4 Soil Classification 18
Fig.3.5 Geo-seismal map of Italy 18
Fig. 4.1 Finite Element Model 21
Fig. 4.2 Support Conditions 22
Fig. 4.3 Design Spectrum for Bridges (Horizental) in Italy (3274) 25
Fig. 4.4 Design Spectrum for Bridges (Vertical) in Italy (3274) 25
Fig. 4.5 Simulated accelerogram (a) Time History (b) Response Spectra 27
Fig. 4.6 Location of PGA at Collapse 29
Fig. 5.1 Deflected Shape 30
Fig. 5.2 Mode Shape 31
Fig. 5.3 Displacement Contours 31
Fig. 5.4 Vibration Mode Shape 1 (Natural Period = 0.00596 Sec) 32
Fig. 5.5 Vibration Mode 2 (Natural Period = 0.00485 Sec) 32
Fig. 5.6 Vibration Mode Shape 3 (Natural Period = 0.00472 Sec) 33
Fig. 5.7 Bending Moment Diagram for 11 span of bridges. 34
Fig. 5.8 Bending Moment Diagram for mid span of bridges. 34
Fig. 5.9 Comparison of actural PGAcap and required PGA at Collapse 38
Fig. 5.10 Comparison of actural PGAcap and required PGA at Severe Damage 38
Fig. 5.11 Comparison of actural PGAcap and required PGA at Limited State 39
Fig. 5.12 Comparison of actural PGAcap and required PGA at Collapse near 40
support
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Fig. 5.13 Comparison of actural PGAcap and required PGA at Severe Damage 41
near support

Fig. 5.14 Comparison of actural PGAcap and required PGA at Limited State near 41
support

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LIST of TABLES
Pages
Table 2.1 Values of specific weight for some types of filling materials 6
Table 2.2 Specification of bridge 13
Table 4.1 Material Properties Used in Analysis 22
Table 4.2 Response Spectrum Parameters (Horizental Direction) 24
Table 4.3 Response Spectrum Parameters (Vertical Direction) 25
Table 4.4 Three Levels Peak Ground Acceleration 27
Table 5.1 Safety coefficient obtained from the worst combination for mid 37
Table 5.2 PGA capacity of the Mid span Arch 37
Table 5.3 Safety Coefficeints to three State 39
Table 5.4 PGA capacity at support span Arch 40

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TABLE OF CONTENTS
Pages
ACKNOWLEDGEMENT i

ABSTRACT ii

LIST OF FIGURES iii

LIST OF TABLES vi

TABLE OF CONTENTS v

CHAPTER 1 INTRODUCTION 1
1.1 Introduction
1.2 Scope 1

CHAPTER 2 ARCH MASONRY BRIDGES 3

2.1 General characteristics of masonry bridges 3
2.2 Structural arrangement 5
2.3 Characteristics of filling material 6
2.4 Seismic damage to masonry bridges 7
2.5 Location of bridge 9

CHAPTER 3 EVALUATION OF SEISMIC SAFETY OF HISTORICAL BRIDGES 14

3.1 Past seismicity in Italy 14
3.2 Seismic Codes 15
3.3 Ordinance 3274 19

CHAPTER 4 DEVEOPMENT OF FEA MODELS FOR BRIDGE 21

4.1 Introduction 21
4.2 Application of the FE method 23
4.3 Materials 24
4.4 Seismic Parameters for FEA Bridge Model 27
4.5 Artificial Accelerogram 26
4.6 Analysis of the Seismic Response of Structure 29
4.7 Method of Analysis 30

CHAPTER 5 EVALUATIONS OF SEISMIC VULNERABILITY 32

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