scholarly journals Comparative analysis of the fragility curves for Italian residential masonry and RC buildings

Author(s):  
Francesca da Porto ◽  
Marco Donà ◽  
Annalisa Rosti ◽  
Maria Rota ◽  
Sergio Lagomarsino ◽  
...  

AbstractThe Department of Civil Protection (DPC), in compliance with the EU decision 1313/2013 and at the request of the Sendai Framework for Disaster Risk Reduction 2015–2030 to update the disaster risk assessments by various countries, released the latest National Risk Assessment for Italy at the end of 2018. Specifically, as regards the seismic risk assessment, six research units belonging to two centres of competence of the DPC collaborated under its guidance to update the risk maps of the Italian residential heritage. This extensive collaboration complied with the recent Italian code for Civil Protection, which requires a broad scientific consensus for risk assessment. During this research activity, six fragility models were developed, according to some common criteria (four for masonry buildings and two for RC buildings). These models were then implemented by the DPC for the definition of the national seismic risk. Within this context, the aim of this paper is to evaluate the risk results provided by these models, compare their features, and assess and validate their prediction capabilities. In particular, this paper shows the comparison of predicted and observed damage scenarios and consequences on building stock and the population of two seismic events, i.e. L’Aquila 2009 and Amatrice 2016. Furthermore, the paper provides some interesting damage and risk predictions at a national level. Overall, the forecasts and comparisons made in this study demonstrate the validity of the approach adopted by the DPC for the assessment of national seismic risk.

Author(s):  
Marco Donà ◽  
Pietro Carpanese ◽  
Veronica Follador ◽  
Luca Sbrogiò ◽  
Francesca da Porto

Abstract Seismic risk assessment at the territorial level is now widely recognised as essential for countries with intense seismic activity, such as Italy. Academia is called to give its contribution in order to synergically deepen the knowledge about the various components of this risk, starting from the complex evaluation of vulnerability of the built heritage. In line with this, a mechanics-based seismic fragility model for Italian residential masonry buildings was developed and presented in this paper. This model is based on the classification of the building stock in macro-typologies, defined by age of construction and number of storeys, which being information available at national level, allow simulating damage scenarios and carrying out risk analyses on a territorial scale. The model is developed on the fragility of over 500 buildings, sampled according to national representativeness criteria and analysed through the Vulnus_4.0 software. The calculated fragility functions were extended on the basis of a reference model available in the literature, which provides generic fragilities for the EMS98 vulnerability classes, thus obtaining a fragility model defined on the five EMS98 damage states. Lastly, to assess the reliability of the proposed model, this was used to simulate damage scenarios due to the 2009 L’Aquila earthquake. Overall, the comparison between model results and observed damage showed a good fit, proving the model effectiveness.


1996 ◽  
Vol 12 (3) ◽  
pp. 371-394 ◽  
Author(s):  
Alex H. Barbat ◽  
Fabricio Yépez Moya ◽  
JoséA. Canas

A methodology for simulating seismic damage of unreinforced masonry buildings for seismic risk assessment of urban areas is presented in this paper. The methodology is based on the Italian vulnerability index and on the results of a post-earthquake damage survey study whose main result was an observed vulnerability function. The Monte Carlo method was then used to simulate damage probability matrices, fragility curves and vulnerability functions, all of which are the basis of a seismic risk study. The simulation process required the generation of thousands of hypothetical buildings, the analysis of their seismic behaviour and probabilistic studies of the computed results. As an example, probable damage scenarios were developed for an urban zone of Barcelona.


Author(s):  
Mauro Dolce ◽  
Andrea Prota ◽  
Barbara Borzi ◽  
Francesca da Porto ◽  
Sergio Lagomarsino ◽  
...  

AbstractThe last National Risk Assessment NRA for Italy was developed at the end of 2018 by the Department of Civil Protection (DPC) in response to the specific requirement of the Sendai Framework for Disaster Risk Reduction 2015–2030 to periodically adjourn the assessment of disaster risk. The methodology adopted to perform seismic risk assessment and build national seismic risk maps was specifically developed to comply with the recent Code for Civil Protection, issuing that, in addition to a solid scientific base, risk assessment should be characterized by a wide consensus of the scientific community. As a result, six research units belonging to two Centers of Competence of the DPC, namely ReLUIS (Network of university laboratories for seismic engineering) and EUCENTRE (European Centre for Training and Research in Earthquake Engineering), collaborated under the guidance and coordination of DPC to produce the recent updating of national seismic risk maps for the residential building stock. This paper describes the methodology adopted to develop the consensus-based national seismic risk assessment and presents the main results in terms of expected damage and impact measures (unusable buildings, homeless, casualties, direct economic losses).


2009 ◽  
Vol 25 (3) ◽  
pp. 619-641 ◽  
Author(s):  
J. S.R. Prasad ◽  
Yogendra Singh ◽  
Amir M. Kaynia ◽  
Conrad Lindholm

A seismic risk assessment methodology based on socioeconomic clustering of urban habitat is presented in this paper. In this methodology, the city is divided into different housing clusters based on socioeconomic level of occupants, representing reasonably uniform seismic risk. It makes an efficient utilization of high resolution satellite data and stratified random sample survey to develop the building stock database. Ten different classes of socioeconomic clusters found in Indian cities are defined and 34 model building types (MBTs) prevalent on the Indian subcontinent have been identified and compared with the Medvedev-Sponheuer-Karnik (MSK) scale, European macroseismic scale (EMS), parameterless scale of seismic intensity (PSI), and HAZUS classifications. Lower and upper bound damage probability matrices (DPMs) are estimated, based on the MSK and EMS intensity scales and experience from past earthquakes in India. A case study of Dehradun, a city in the foothills of Himalayas, is presented. The risk estimates using the estimated DPMs have been compared with those obtained using the PSI scale. It has been observed that poorer people are subjected to higher seismic risk, both in terms of casualties and in terms of percent economic losses.


2017 ◽  
Author(s):  
Jidong Wu ◽  
Xu Wang ◽  
Elco Koks

Abstract. Exposure is an integral part of any natural disaster risk assessment. As one of the consequences of natural disasters, damage to buildings is one of the most important concerns. As such, estimates of the building stock and the values at risk can assist natural disaster risk management, including determining the damage extent and severity. Unfortunately, only little information about building asset value is readily available in most countries (especially its spatial distributions) including in China, given that the statistical data on building floor area (BFA) is collected by administrative unities in China. In order to bridge the gap between aggregated census statistical buildings floor-area data to geo-coded building asset value data, this article introduces a methodology for a city-scale building asset value mapping using Shanghai as an example. It consists of a census BFA disaggregation (downscaling) by means of a building footprint map extracted from high-resolution remote sensing data and LandScan population density data, and a financial appraisal of building asset values. A validation with statistical data confirms the feasibility of the modelled building storey. The example of the use of the developed building asset value map in exposure assessment of a flood scenario of Shanghai demonstrated that the dataset offers immense analytical flexibility for flood risk assessment. The method used in this paper is transferable to be applied in other cities of China for building asset value mapping.


Author(s):  
Nina N. Serdar ◽  
Jelena R. Pejovic ◽  
Radenko Pejovic ◽  
Miloš Knežević

<p>It is of great importance that traffic network is still functioning in post- earthquake period, so that interventions in emergency situations are not delayed. Bridges are part of the traffic system that can be considered as critical for adequate post-earthquake response. Their seismic response often dominate the response and reliability of overall transportation system, so special attention should be given to risk assessment for these structures. In seismic vulnerability and risk assessment bridges are often classified as regular or irregular structures, dependant on their configuration. Curved bridges are considered as irregular and unexpected behaviour during seismic excitation is noticed in past earthquake events. Still there are an increasing number of these structures especially in densely populated urban areas since curved configuration is often suitable to accommodate complicated location conditions. In this paper special attention is given to seismic risk assessment of curved reinforce concrete bridges through fragility curves. Procedure for developing fragility curves is described as well as influence of radius curvature on their seismic vulnerability is investigated. Since vulnerability curves provide probability of exceedance of certain damage state, four damage states are considered: near collapse, significant damage, intermediate damage state, onset of damage and damage limitation. As much as possible these damage states are related to current European provisions. Radius of horizontal curvature is varied by changing subtended angle: 25 °, 45 ° and 90 °. Also one corresponding straight bridge is analysed. Nonlinear static procedure is used for developing of fragility curves. It was shown that probability of exceedance of certain damage states is increased as subtended angle is increased. Also it is determined that fragility of curved bridges can be related to fragility of straight counterparts what facilitates seismic evaluation of seismic vulnerability of curved bridges structures.</p>


Structures ◽  
2021 ◽  
Vol 32 ◽  
pp. 889-913
Author(s):  
Moustafa Moufid Kassem ◽  
Fadzli Mohamed Nazri ◽  
Ehsan Noroozinejad Farsangi ◽  
Chee Ghuan Tan

2020 ◽  
Author(s):  
Christine Prokopf

How do we as a society cope with future hazards? In an increasing number of German policy areas, ‘risk’ is a key term in important policy documents. Risk may then give rise to the idea of risk governance, which implies the analysis, assessment and management of risks in a sustained societal process. This conceptualisation of risk governance allows us to normatively focus political action on disaster prevention instead of on coping with disasters after they have occurred. This study analyses policy translation from an international to a national level in terms of the EU flood risk management directive, the approach to risk analysis used by the German Federal Agency for civil protection and the Sendai Framework for Disaster Risk Reduction to find out if the potential of risk governance is being exploited and how extensively responsibility is being transferred from the state to citizens in this process. Finally, the author concludes that several important factors hinder a normative shift towards disaster prevention.


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