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2014 | Buch

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SYNER-G: Typology Definition and Fragility Functions for Physical Elements at Seismic Risk

Buildings, Lifelines, Transportation Networks and Critical Facilities

herausgegeben von: K. Pitilakis, H. Crowley, A.M. Kaynia

Verlag: Springer Netherlands

Buchreihe : Geotechnical, Geological and Earthquake Engineering

Enthalten in: Springer Professional "Wirtschaft+Technik" , Springer Professional "Technik" , Springer Professional "Wirtschaft"

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Über dieses Buch

Fragility functions constitute an emerging tool for the probabilistic seismic risk assessment of buildings, infrastructures and lifeline systems. The work presented in this book is a partial product of a European Union funded research project SYNER-G (FP7 Theme 6: Environment) where existing knowledge has been reviewed in order to extract the most appropriate fragility functions for the vulnerability analysis and loss estimation of the majority of structures and civil works exposed to earthquake hazard. Results of other relevant European projects and international initiatives are also incorporated in the book. In several cases new fragility and vulnerability functions have been developed in order to better represent the specific characteristics of European elements at risk. Several European and non-European institutes and Universities collaborated efficiently to capitalize upon existing knowledge. State-of-the-art methods are described, existing fragility curves are reviewed and, where necessary, new ones are proposed for buildings, lifelines, transportation infrastructures as well as for utilities and critical facilities. Taxonomy and typology definitions are synthesized and the treatment of related uncertainties is discussed.

A fragility function manager tool and fragility functions in electronic form are provided on extras.springer.com.

Audience

The book aims to be a standard reference on the fragility functions to be used for the seismic vulnerability and probabilistic risk assessment of the most important elements at risk. It is of particular interest to earthquake engineers, scientists and researchers working in the field of earthquake risk assessment, as well as the insurance industry, civil protection and emergency management agencies.

Inhaltsverzeichnis

Frontmatter

Chapter 1. Introduction

Abstract

This chapter outlines the main components, parameters and methods to derive fragility functions, which can be used in seismic risk assessment of different engineering systems and components at urban and regional scale. It provides the means of understanding the main factors governing this topic, introducing the subjects that will be extensively described and discussed in the subsequent chapters, where the fragility curves for buildings and all important components of the systems and infrastructures will be described in detail.

Kyriazis Pitilakis, Helen Crowley, Amir M. Kaynia

Chapter 2. Modeling and Propagation of Uncertainties

Abstract

The basic problem dealt with in this chapter consists in finding the distribution of a scalar quantity Y which is a function of a vector X of probabilistically qualified random quantities. The dependence of Y on X is not explicit, requiring algorithms for its determination. An approach that facilitates the solution of the problem was first adopted in problems of nuclear safety, and consists in expressing the probability of Y exceeding a given value (if Y has a monetary connotation), or a given structural Limit-State of a whole system, as a multiple integral of a Markov chain of conditional probability functions. This approach is described in this chapter with reference to buildings, but the approach can be equally applied to various industrial systems. A crucial step in the chain is the passage from the intensity of the action, in the present case the intensity of the ground motion, to the vector of the structural response variables on which the state of the system, and ultimately Y, depend. This passage involves consideration of the variability of the action, in the form of different samples of ground motion together with all the uncertainties inherent in the numerical determination of the response, which include those related to the selection of the structural model and the uncertainties of its parameters. A number of approximate techniques for dealing with this problem are presented, starting from the simple but inadequate FOSM method, to the approach based on the use of a Response Surface in the space of the structural variables, and concluding with the potentially more accurate Latin Hypercube Sampling technique, underlining however its practical limits due to the computational effort required for large number of uncertain quantities.

Paolo Emilio Pinto

Chapter 3. Evaluation of Existing Fragility Curves

Abstract

There is a wealth of existing fragility curves for buildings and infrastructure. The main challenge in using these curves for future applications is how to identify and, if necessary, combine suitable fragility curves from a pool of curves with different characteristics and, often unknown, reliability. The present chapter aims to address this challenge by developing a procedure which identifies suitable fragility curves by firstly assessing their representativeness to the needs of the future application and then assessing the reliability of the most relevant relationships. The latter is based on a novel procedure which involves the assessment of the most significant factors affecting the robustness and quality for each fragility assessment methodology, also presented here. In addition, a decision-tree approach is adopted in order to combine more than one suitable fragility curves. The proposed selection and combination procedures are illustrated here with a simple case study which appraises the impact of different weighting schemes and highlights the importance of a deep understanding of the existing fragility curves and their limitations.

Tiziana Rossetto, Dina D’Ayala, Ioanna Ioannou, Abdelghani Meslem

Chapter 4. Epistemic Uncertainty in Fragility Functions for European RC Buildings

Abstract

This chapter briefly summarises the work carried out under the auspices of the SYNER-G project to collect, harmonize and compare fragility functions for European RC buildings. All of these functions have been stored in the Fragility Function Manager described in Chap. 13. Examples of a methodology for estimating the epistemic uncertainty across a collection of fragility functions is presented, which, as discussed herein, should first be carefully reviewed for reliability, for example following the methodology presented in Chap. 3.

Helen Crowley, Miriam Colombi, Vitor Silva

Chapter 5. Fragility Functions of Masonry Buildings

Abstract

This chapter proposes a method for the vulnerability assessment of ordinary masonry buildings at territorial scale, to be used in the framework of a probabilistic seismic risk analysis. The classification of the built environment is based on the SYNER-G taxonomy and is dependent on the available data in the study area; it consists in the aggregation of buildings characterized by a homogeneous seismic behavior, which is known from empirical damage on similar structures, proper analytical models or expert judgment. The general definition of fragility functions is recalled, through the use of static non linear analysis for the evaluation of the capacity spectrum and the calculation of the maximum displacement by the demand spectrum. The selection of proper intensity measures for masonry buildings is treated, as well as the definition of damage and performance limit states. A detailed procedure for the propagation of uncertainties is proposed, which is able to single out each independent contribution. Then, some recommendations for deriving fragility functions with different approaches are given. In particular, it is shown how the macroseismic vulnerability method, derived from EMS98, can be used by expert elicitation or if empirical data are available. Moreover, the DBV-masonry (Displacement Based Vulnerability) method is proposed as a powerful tool for the derivation of fragility function by an analytical approach. Finally, fragility functions are derived for ten different classes of masonry buildings, defined by a list of tags from the taxonomy, in order to show the capabilities of the proposed methods and their cross-validation.

Sergio Lagomarsino, Serena Cattari

Chapter 6. Fragility Functions of Electric Power Stations

Abstract

This chapter presents a state-of-the-art on fragility models for the components of Electric Power Networks (EPNs) available in the technical literature. First, the main characteristics of an electric power network and its taxonomy are introduced. Then, the main recent works on fragility functions of electric components are listed, and details are provided for a few selected ones. In the last section, the fragility curves which are most suited for use in the European context are selected, with the indication of parameters and relevant information. The selection has been based both on the data supporting the models and on the adopted systemic approach to the simulation of EPN within the SYNER-G general methodology for infrastructural systems’ vulnerability assessment. The latter adopts a capacitive, detailed flow-based modelling with short-circuits propagation over the network and requires the modelling of the substation internal logic.

Francesco Cavalieri, Paolo Franchin, Paolo Emilio Pinto

Chapter 7. Fragility Functions of Gas and Oil Networks

Abstract

The present chapter aims to present and review fragility curves for components of gas and oil system networks. These fragility functions need to be applicable to the specific European context and they should be available for a variety of network components such as buried pipelines, storage tanks and processing facilities (i.e. compression and reduction stations). Based on a literature review, it is found that the available fragility functions are mostly empirical and should be applied to the European context, given the current lack of data needed to validate potential analytical methods of vulnerability assessment. For buried pipelines, fragility relations are reviewed with respect to both wave propagation and ground failure. Existing fragility curves for storage tanks and processing facilities are also critically appraised, according to the modelling assumptions and the derivation techniques (e.g. fault-tree analysis, numerical simulation or empirical relation).

Pierre Gehl, Nicolas Desramaut, Arnaud Réveillère, Hormoz Modaressi

Chapter 8. Fragility Functions of Water and Waste-Water Systems

Abstract

This chapter presents the state-of-the-art on the fragility models for the vulnerability assessment of the water and waste-water networks’ components. First, the main characteristics and typologies of the two networks’ components such as water sources, treatment plants, pumping and lift stations, tanks and conduits are introduced. Then, the main damage mechanisms and failure modes are summarized for each component based on the experiences from past earthquakes. A literature review of existing fragility models is performed including damage scales, seismic intensity measures and fragility functions. Finally, the fragility functions which are most suited for use in the European context are proposed, together with their parameters and relevant information.

Kalliopi Kakderi, Sotiris Argyroudis

Chapter 9. Fragility Functions of Road and Railway Bridges

Abstract

This Chapter presents a literature review of seismic fragility functions for reinforced concrete road and railway bridges. It first covers the main issues in fragility analysis, such as the systems for classification of bridges, methods for deriving fragility functions, intensity measures, damage states and damage measures. A section is dedicated to the way the uncertainties regarding the seismic action, geometry, material properties and modelling are treated in existing studies. The Chapter deals also with the recent developments that examine special issues which were not addressed in the first generation of fragility curves. They refer to damaged and retrofitted bridges, the effects of corrosion, skew, spatial variability of the seismic action and liquefaction. Finally, a method for fast fragility analysis of regular bridges is presented. The method applies to bridges with continuous deck monolithically connected to the piers or supported on elastomeric bearings and with free or constrained transverse translation at the abutments.

Georgios Tsionis, Michael N. Fardis

Chapter 10. Fragility Functions of Highway and Railway Infrastructure

Abstract

The experience of past earthquakes has revealed that highway and railway elements are quite vulnerable to earthquake shaking and induced phenomena such as soil liquefaction or landslide; damages to these elements can seriously affect the transportation of products and people in both short-term (emergency actions) and long-term period. The objective of this chapter is to propose appropriate fragility functions for roadway and railway components other than bridges that are presented separately in Chap. 9. To this end, the main typological features are summarized and a short review of earthquake damages together with damage states definitions are provided for these elements. Fragility curves from literature are collected and reviewed. In some cases these functions are modified and adapted, while in other cases new fragility curves are developed. A general procedure for the derivation of analytical fragility curves that was followed in SYNER-G is described. This approach takes into account the effect of structure geometry, ground motion characteristics, soil conditions and associated uncertainties. New fragility curves are presented for tunnels in soil, embankments, cuttings and bridge abutments based on numerical analyses due to ground shaking. Finally, the proposed fragility functions are summarized and a general scheme to identify the functionality of roadway and railway elements due to different damage levels is outlined.

Sotiris Argyroudis, Amir M. Kaynia

Chapter 11. Fragility Functions of Harbor Elements

Abstract

Experience gained from recent strong seismic events has demonstrated the high vulnerability of waterfront structures and port facilities to strong ground shaking and associated phenomena resulting to severe physical damages and important economic losses. The objective of this Chapter is to review and propose fragility curves and methods to assess the seismic vulnerability for the most important components of a harbor system, namely waterfront structures, cargo handling and storage components and infrastructures within the European context in terms of construction practice and seismicity. After a short review, the observed during past earthquakes different failure modes are identified and classified and a detailed taxonomy is proposed with special emphasis to European specific features. Based on the taxonomy and the proposed classification of the different elements at risk, adequate fragility curves are provided.

Kalliopi Kakderi, Kyriazis Pitilakis

Chapter 12. Component Fragilities and System Performance of Health Care Facilities

Abstract

Hospitals belong to the so-called “complex-social” systems since they depend on several components of different nature to function properly and they provide a societal service to citizens. The basic components of a hospital are: the staff, the organization and the facility. They jointly “contribute” to provide medical care to patients. This chapter focus on the seismic assessment of the facility. A hospital has to be capable of providing medical after the occurrence of a major earthquake; hence the facility target performance is set as operational. Such a performance depends on the response of both structural and non-structural elements. Fragility curves for “typical” non-structural elements are provided. A probabilistic-based procedure for the evaluation of the fragility curve of the facility is then derived. Finally, an index adequate to measure the performance of the hospital under emergency condition is proposed.

Alessio Lupoi, Francesco Cavalieri, Paolo Franchin

Chapter 13. Fragility Function Manager Tool

Abstract

This chapter describes the SYNER-G Fragility Function Manager, which has been developed to store, visualize and manage a large number of fragility function sets. The tool can store functions for a wide range of elements at risk, and has features that allow these functions to be harmonized (in terms of intensity measure type and limit state) and then compared. The tool is provided, together with a collection of European fragility functions, as an electronic supplement to this book.

Vitor Silva, Helen Crowley, Miriam Colombi

Chapter 14. Recommendations for Future Directions in Fragility Function Research

Abstract

This chapter outlines the main comments relevant to the compilation of fragility functions and highlights the main recommendations given in the different Chapters of this Book concerning the selection among existing fragility functions or the derivation of new ones for the most important elements at risk. Essential needs for future studies are also summarized.

Kyriazis Pitilakis, Helen Crowley

Backmatter

Titel: SYNER-G: Typology Definition and Fragility Functions for Physical Elements at Seismic Risk
herausgegeben von: K. Pitilakis
H. Crowley
A.M. Kaynia
Verlag: Springer Netherlands
Electronic ISBN: 978-94-007-7872-6
Print ISBN: 978-94-007-7871-9
DOI: https://doi.org/10.1007/978-94-007-7872-6