scholarly journals NODE: a large‐scale seismic risk prioritization tool for Italy based on nominal structural performance

2021 ◽  
Author(s):  
Fabio Petruzzelli ◽  
Iunio Iervolino
Keyword(s):  
Seismic Risk ◽  
Large Scale ◽  
Seismic Vulnerability ◽  
Risk Mitigation ◽  
Risk Measure ◽  
Computational Effort ◽  
Specific Reference ◽  
Stock Management ◽  
Building Stock ◽  
Italian Case

AbstractPrioritization of seismic risk mitigation at a large scale requires rough-input methodologies able to provide an expedited, yet conventional, assessment of the seismic risk corresponding to the portfolio of interest. In fact, an evaluation of seismic vulnerability at regional level by means of mechanics-based methods is generally only feasible for a fraction of the portfolio, selected according to prioritization criteria, due to the sheer volume of information and computational effort required. Therefore, conventional assessment of seismic risk via simple indices has been proposed in literature and in some guidelines, mainly based on the comparison of code requirements at the time of design and current seismic demand. These indices represent an attempt to define a relative seismic risk measure for a rapid ranking to identify the part of the portfolio that deserves further investigation. Although these risk metrics are based on strong assumptions, they have the advantage of only requiring easy-to-retrieve data, such as design year and location as the bare minimum, making them suitable for applications within the risk analysis industry. Moreover, they can take both hazard and vulnerability into account, albeit conventionally, and can be manipulated in order to account for exposure in terms of individual or societal risks. In the present study, the main assumptions, limitations, and possible evolutions of existing prioritization approaches to nominal risk are reviewed, with specific reference to the Italian case. Furthermore, this article presents the software NODE (available to interested readers), which enables the computation of location-specific code-based seismic performance demands, according to the Italian code and the evolution of seismic classification since 1909. Finally, this study intends to contribute to the ongoing debate on strategies for large-scale seismic assessment for building stock management purposes.

scholarly journals Simplified Seismic Vulnerability Assessment Methods: A Comparative Analysis with Reference to Regional School Building Stock in Italy

2020 ◽  
Vol 10 (19) ◽  
pp. 6771
Author(s):  
F. Ceroni ◽  
N. Caterino ◽  
A. Vuoto
Keyword(s):  
Large Scale ◽  
Seismic Vulnerability ◽  
Computational Effort ◽  
School Buildings ◽  
Existing Buildings ◽  
Building Stock ◽  
Output Data ◽  
Seismic Vulnerability Assessment ◽  
Data Limitations ◽  
Available Information

The paper compares several simplified methods proposed in the literature for assessing the seismic vulnerability of existing buildings. Type and number of input and output data, limitations of use for different structural typologies, and complexity of use are examined for each methodology to identify the most suitable for assessing the vulnerability of a given class of buildings, based on the available data, the computational effort, and the type of vulnerability judgment. The selected methods were applied to a sample of school buildings located in the province of Naples (Italy). Data were available due to a digital platform and were used to verify the possibility of providing reliable large scale vulnerability judgments based on a reduced set of information, without carrying out additional surveys. The most simplified methods were applied to a sample of about a thousand of buildings, while more detailed methods, needing more information, were applied to a smaller sample. The comparison between the results obtained from different methods allows highlighting advantages and weaknesses of each, so as to identify the convenience in their use according to the specific available information and the objectives of the analysis, finally to evaluate which is more or less safe.

Seismic Risk Mitigation of Historical Masonry Towers by Means of Prestressing Devices

2010 ◽  
Vol 133-134 ◽  
pp. 843-848 ◽  
Author(s):  
Adolfo Preciado Quiroz ◽  
Silvio T. Sperbeck ◽  
Harald Budelmann ◽  
Gianni Bartoli ◽  
Elham Bazrafshan
Keyword(s):  
Seismic Risk ◽  
Seismic Vulnerability ◽  
Risk Mitigation ◽  
Numerical Models ◽  
Failure Mechanisms ◽  
Masonry Towers ◽  
Seismic Risk Mitigation ◽  
Historical Masonry ◽  
Observed Damage ◽  
And Behavior

This work presents the investigation of the efficiency of different prestressing devices as a rehabilitation measure for the seismic risk mitigation of historical masonry towers. As a first phase, the seismic vulnerability of theoretical masonry towers was assessed by means of numerical models validated with information from the literature, observed damage and behavior of these structures due to passed earthquakes (crack pattern and failure mechanisms), and mainly taking into account the engineering experience. Afterwards, the validated models were rehabilitated with different prestressing devices; analyzing the results and concluding which device or the combination of them improved in a better way the seismic performance of the masonry towers. Finally, the methodology will be applied in two historical masonry towers located in seismic areas; the medieval tower “Torre Grossa” of San Gimignano, Italy, and one of the bell towers of the Cathedral of Colima, Mexico.

Development of An Exposure Model for Bridge Structures in Northern Algeria

2018 ◽  
Author(s):  
Andrés Abarca ◽  
Ricardo Monteiro
Keyword(s):  
Risk Assessment ◽  
Large Scale ◽  
Risk Mitigation ◽  
Regional Scale ◽  
Mitigation Measures ◽  
Exposure Model ◽  
Building Stock ◽  
Earthquake Scenarios ◽  
Northern Algeria ◽  
Bridge Structures

In recent years, the use of large scale seismic risk assessment has become increasingly popular to evaluate the fragility of a specific region to an earthquake event, through the convolution of hazard, exposure and vulnerability. These studies tend to focus on the building stock of the region and sometimes neglect the evaluation of the infrastructure, which has great importance when determining the ability of a social group to attend to a disaster and to eventually resume normal activities. This study, developed within the scope of the EU-funded project ITERATE (Improved Tools for Disaster Risk Mitigation in Algeria), focuses on the proposal of an exposure model for bridge structures in Northern Algeria. The proposed model was developed using existing national data surveys, as well as satellite information and field observations. As a result, the location and detailed characterization of a significant share of the Algeria roadway bridge inventory was developed, as well as the definition of a taxonomy that is able to classify the most common structural systems used in Algerian bridge construction. The outcome of this study serves as input to estimate the fragility of the bridge infrastructure inventory and, furthermore, to the overall risk assessment of the Northern Algerian region. Such fragility model will, in turn, enable the evaluation of earthquake scenarios at a regional scale and provide valuable information to decision makers for the implementation of risk mitigation measures.

The role of risk measures in making seismic upgrading decisions

2020 ◽  
Vol 36 (4) ◽  
pp. 1802-1822
Author(s):  
Lukas Bodenmann ◽  
Panagiotis Galanis ◽  
Marco Broccardo ◽  
Božidar Stojadinović
Keyword(s):  
Seismic Risk ◽  
Financial Risk ◽  
Risk Mitigation ◽  
Risk Measures ◽  
Risk Measure ◽  
Full Range ◽  
Financial Benefit ◽  
Financial Benefits ◽  
Risk Appetite

Risk measures are tools that enable consistent measurement of financial risk and quantify the risk exposure to an associated hazard. In finance, there is a broad spectrum of risk measures which reflect different asset performance goals and the risk appetite of the decision-maker. In this study, the authors leverage advancements in financial risk management to examine the role of risk measures to quantify the seismically induced financial risk, measure the benefit of seismic upgrading, and relate the benefit of seismic risk reduction to a degree of the implemented seismic upgrade. The findings demonstrate that the relation between the financial benefits of a seismic upgrade, quantified using risk measures that consider the full range of earthquake events, and the degree of the seismic upgrade are concave, that is, the incremental financial benefit reduces gradually with increasing degree of seismic upgrading. The opposite holds if the risk measures consider only the high-severity low-likelihood events. Therefore, the study shows that the selection of the risk measure plays a crucial role in determining the target degree of seismic upgrading. Equivalently, quantifying the financial benefits of seismic risk mitigation using different risk measures might lead to different seismic upgrading decisions for the same structure.

Large-Scale Seismic Vulnerability Assessment Method for Urban Centres. An Application to the City of Florence

2014 ◽  
Vol 628 ◽  
pp. 49-54 ◽  
Author(s):  
Maurizio Ripepe ◽  
Giorgio Lacanna ◽  
Pauline Deguy ◽  
Mario de Stefano ◽  
Valentina Mariani ◽  
...  
Keyword(s):  
Vulnerability Assessment ◽  
Large Scale ◽  
Seismic Vulnerability ◽  
Risk Mitigation ◽  
Structural Features ◽  
Assessment Method ◽  
Ground Acceleration ◽  
Seismic Vulnerability Assessment ◽  
Damage Scenarios ◽  
The City

The seismic vulnerability assessment of a building requires a comprehensive knowledge of both building structural features and soils geophysical parameters. To achieve a vulnerability assessment at the urban scale a large amount of data would be necessary, with a consequent involvement of time and economical resources. The aim of this paper is hence to propose a simplified procedure to evaluate the seismic vulnerability of urban centres and possible seismic damage scenarios in order to identify critical areas and/or building typologies to plan future actions of seismic risk mitigation and prevention. The procedure is applied to the outstanding case study of the city of Florence. The research is based on the definition of major building typologies related to construction periods and type of the structural system (masonry or reinforced concrete), the identification of a set of sample buildings, the analysis of the dynamic behaviour and the evaluation of a vulnerability index with an expeditious approach. The obtained results allow to define potential vulnerability and post-event damage scenarios related to the expected levels of peak ground acceleration.

SEISMIC RETROFIT OF NONDUCTILE REINFORCED CONCRETE FRAME AND MASONRY BUILDINGS

2019 ◽  
Vol 2 (Special Issue on First SACEE'19) ◽  
pp. 143-164
Author(s):  
Murat Saatcioglu
Keyword(s):  
Reinforced Concrete ◽  
Seismic Risk ◽  
Seismic Vulnerability ◽  
Risk Mitigation ◽  
Seismic Retrofit ◽  
Masonry Wall ◽  
System Level ◽  
Reinforced Concrete Frame ◽  
Existing Building ◽  
Concrete Frame

A large proportion of existing building and bridge infrastructure across the world consists of seismically deficient non-ductile structural systems. Performance of structures during recent earthquakes have demonstrated seismic vulnerability of these systems, the majority of which were designed prior to the enactment of modern seismic codes, though some were designed more recently in areas where code enforcement provides challenges. These structures constitute considerable seismic risk, especially in large metropolitan centres. Because it is economically not feasible to replace a large segment of seismically deficient infrastructure with new and improved systems, retrofitting existing structures remains to be a viable seismic risk mitigation strategy. The objective of this paper is to highlight seismic retrofit strategies for deficient building and bridge infrastructures, with emphasis on experimental and analytical research conducted at the University of Ottawa. The retrofit strategies consist of structural upgrades at the system level, as well as at the element level. Non-ductile reinforced concrete frame retrofits, in the form of lateral bracing techniques, and concrete column and masonry wall retrofit methodologies are discussed. The use of innovative materials and techniques are presented.

Integrated methodologies for seismic risk mitigation in Durrës (Albania) after the seismic event of November 26th, 2019

2021 ◽  
Author(s):  
Elfrida Shehu ◽  
Klodian Skrame
Keyword(s):  
Seismic Risk ◽  
Seismic Vulnerability ◽  
Risk Mitigation ◽  
Housing Prices ◽  
Point Of View ◽  
Earthquake Ground Motion ◽  
Emergency Plans ◽  
Rapid Urbanization ◽  
The Impact ◽  
The City

<p>Albania, the small country in the western Balkan, is a disaster-prone country. It ranks as one of the countries in the world with the highest economic risk from natural hazards events. During the past several decades, in average, Albania has been hit by about one major geological event per year. The impact of disasters in Albania are significantly compounded by a relatively high degree of poverty, lack of infrastructure maintenance, unsafe building and land use practices, linked to rapid urbanization, exploitation of natural resources (overgrazing of pasture, overexploitation of forests and riverbeds, etc.) as well as some other consequences of the transition from a centralized to an open marked economy.</p><p>From a geological point of view, Albania is a young and very dynamic territory and is very vulnerable to the geological and hydro-geological hazards as: earthquakes, landslides, flooding, torrential rains, river erosion, coastal erosion and avalanches that cover almost the entire territory. Due to these conditions its average annual losses count for about 2.5% of its GDP.</p><p>The Durrës earthquakes of 2019 had a huge impact on the Albanian economy. The city of Durrës, Thumanë, Tirana, Vora, Shijak and their villages suffered considerable damage after the earthquakes of September 21<sup>st</sup>, 2019 of Mw 5.4 and November 26<sup>th</sup>, 2019 of Mw 6.2. The main event of the <sup>26th</sup> November caused the deaths of 51 persons and the damaging of hundreds of buildings. The degree of damages produced by these earthquakes has been, in some cases, significantly enhanced by the characteristics of the earthquake ground motion affected by the local subsurface soil structure and the quality of the constructions. The situations during and after the seismic events highlight the indispensable need of the seismic microzonation studies for the entire Albanian territory and emergency plans for the main cities of the country.</p><p>This paper shows the impact of the earthquake event on the housing market value by treating the data collected in the city of Durrës for the period December 2019 - September2020.</p><p>The main goal of the paper is to correlate the obtained results with the engineering-geological and geophysical conditions of the city of Durrёs and the seismic vulnerability of the building.</p><p>The findings of this study can be considered as a first step for in-depth studies aiming to calculate the impact of seismic risk and the change in the risk perception on the housing prices.</p>

Typological Seismic Risk Maps for Italy

2011 ◽  
Vol 27 (3) ◽  
pp. 907-926 ◽  
Author(s):  
Maria Rota ◽  
Andrea Penna ◽  
Claudio Strobbia ◽  
Guido Magenes
Keyword(s):  
Seismic Risk ◽  
Risk Mitigation ◽  
Fragility Curves ◽  
Reliable Data ◽  
Mitigation Strategies ◽  
Building Stock ◽  
Risk Mitigation Strategies ◽  
Hazard Vulnerability ◽  
Risk Maps ◽  
Italian Territory

This paper describes the methodology followed to derive typological seismic risk maps for Italy and then presents the results. In its classical definition, seismic risk is obtained from the convolution of hazard, vulnerability and exposure. Due to the absence of reliable data on exposure for the entire Italian territory, this study proposes typological seismic risk maps, obtained by simply convolving hazard and vulnerability for several building typologies characteristic of the Italian building stock. A specific hazard study in terms of PGA has been carried out. The results have then been convolved with empirical typological fragility curves, that were derived from data collected during post-earthquake surveys after the main Italian events of the last 30 years. Useful applications can be found for the typological seismic risk maps, both for risk mitigation strategies and for purely economical evaluations (e.g., insurance and reinsurance studies).

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