scholarly journals Mechanics-based fragility curves for Italian residential URM buildings

2020 ◽  
Author(s):  
Marco Donà ◽  
Pietro Carpanese ◽  
Veronica Follador ◽  
Luca Sbrogiò ◽  
Francesca da Porto
Keyword(s):  
Reference Model ◽  
Fragility Curves ◽  
National Level ◽  
Building Stock ◽  
Damage Scenarios ◽  
Complex Evaluation ◽  
Proposed Model ◽  
2009 L’Aquila Earthquake ◽  
Damage States ◽  
Observed Damage

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.

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

2021 ◽  
Author(s):  
Francesca da Porto ◽  
Marco Donà ◽  
Annalisa Rosti ◽  
Maria Rota ◽  
Sergio Lagomarsino ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Seismic Risk ◽  
Fragility Curves ◽  
National Level ◽  
Disaster Risk ◽  
Civil Protection ◽  
Rc Buildings ◽  
Research Activity ◽  
Building Stock ◽  
Damage Scenarios

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.

scholarly journals Relationships between empirical damage and direct/indirect costs for the assessment of seismic loss scenarios

2021 ◽  
Author(s):  
Marco Di Ludovico ◽  
Giuseppina De Martino ◽  
Andrea Prota ◽  
Gaetano Manfredi ◽  
Mauro Dolce
Keyword(s):  
Empirical Data ◽  
Residential Buildings ◽  
Fragility Curves ◽  
Unit Cost ◽  
Indirect Costs ◽  
Mitigation Strategies ◽  
Damage State ◽  
Reconstruction Process ◽  
2009 L’Aquila Earthquake ◽  
Damage States

AbstractThe definition of relationships between damage and losses is a crucial aspect for the prediction of seismic effects and the development of reliable models to define risk maps, loss scenarios and mitigation strategies. The paper focuses on the analysis of post-earthquake empirical data to define relationships between buildings’ damage expressed as usability rating or as global damage state and the associated costs for repair (i.e. direct costs) or for population assistance (i.e. a part of total indirect costs). The analysis refers to the data collected on residential buildings damaged by 2009 L'Aquila earthquake. For different usability rating or damage states, the paper presents the costs expressed in terms of percentage with respect to the reference unit cost of a new building (%Cr and %Ca for repair and population assistance costs, respectively). In particular, the costs analysis refers to undamaged, lightly or severely damaged buildings classified according to usability rating (i.e. A, B-C or E according to Italian classification) or to five different global Damage States (DSs). DSs comply with European Macroseismic Scale (EMS-98) and derive from literature available matrices properly defined to convert empirical damage to structural and non-structural components into building global damage. The %Cr probability density functions and relevant statistics derive from the analysis of actual data of post-earthquake reconstruction process, while, to determine those related to %Ca, a deep analysis of population assistance types, person/month assistance cost for each assistance form, and a methodology to associate such costs to each building are herein presented and discussed. Finally, the paper presents a relationship calibrated on empirical data to directly correlate repair costs on a building with assistance costs to their occupants. The relationships between empirical damage and direct and indirect costs herein presented are of paramount importance because they allow reliable loss scenarios to be defined by simply using literature fragility curves (defined according to empirical or mechanical approaches) aimed at evaluating the probability of exceeding different usability rating or damage states of existing buildings.

scholarly journals A Multilevel Procedure at Urban Scale to Assess the Vulnerability and the Exposure of Residential Masonry Buildings: The Case Study of Pordenone, Northeast Italy

Heritage ◽  
2020 ◽  
Vol 3 (4) ◽  
pp. 1433-1468
Author(s):  
Marco Vettore ◽  
Marco Donà ◽  
Pietro Carpanese ◽  
Veronica Follador ◽  
Francesca da Porto ◽  
...  
Keyword(s):  
Residential Buildings ◽  
Fragility Curves ◽  
Multicriteria Analysis ◽  
Residential Building ◽  
Mechanical Analysis ◽  
Masonry Buildings ◽  
Building Stock ◽  
Damage Scenarios ◽  
Residential Building Stock ◽  
Definition Of

More than the 60% of the Italian residential building stock had already been built by 1974, when seismic codes were enforced on a minimal part of the country. Unreinforced masonry buildings represent most of that share, but they are typical for each region, in terms of both materials and structural configurations. The definition of ‘regional’, i.e., more specific, vulnerability and exposure models are required to improve existing forecast models. The research presents a new geographic information system (GIS)-based multilevel procedure for earthquake disaster prevention planning at urban scale; it includes multicriteria analysis, such as architectural types, structural vulnerability analysis, microzonation studies, and socio-economic aspects. The procedure has been applied to the municipality of Pordenone (PN), a district town of the Friuli–Venezia–Giulia region, in Northeast Italy. To assess the urban seismic risk, more than 5000 masonry residential buildings were investigated and common types within sub-municipal areas and exposure data were collected. Simplified mechanical analysis provided a ‘regional’ vulnerability model through typological fragility curves. The integration of results into GIS tool permitted the definition of cross-mapping among vulnerability, damage scenarios (conditional and unconditional) and exposure (seismic losses, casualties, impact), with respect to various earthquake intensities expected in the town. These results are presented at different scales: from the single building, to submunicipal area and to the entire town.

scholarly journals Nonlinear Dynamic Analysis of Masonry Buildings and Definition of Seismic Damage States

2016 ◽  
Vol 10 (1) ◽  
pp. 192-209 ◽  
Author(s):  
A.J. Kappos ◽  
V.K. Papanikolaou
Keyword(s):  
Fragility Curves ◽  
Pushover Analysis ◽  
Nonlinear Dynamic Analysis ◽  
Critical Issue ◽  
Seismic Damage ◽  
Masonry Building ◽  
Nonlinear Behaviour ◽  
Building Stock ◽  
Damage States ◽  
Diaphragm Action

A large part of the building stock in seismic-prone areas worldwide are masonry structures that have been designed without seismic design considerations. Proper seismic assessment of such structures is quite a challenge, particularly so if their response well into the inelastic range, up to local or global failure, has to be predicted, as typically required in fragility analysis. A critical issue in this respect is the absence of rigid diaphragm action (due to the presence of relatively flexible floors), which renders particularly cumbersome the application of popular and convenient nonlinear analysis methods like the static pushover analysis. These issues are addressed in this paper that focusses on a masonry building representative of Southern European practice, which is analysed in both its pristine condition and after applying retrofitting schemes typical of those implemented in pre-earthquake strengthening programmes. Nonlinear behaviour is evaluated using dynamic response-history analysis, which is found to be more effective and even easier to apply in this type of building wherein critical modes are of a local nature, due to the absence of diaphragm action. Fragility curves are then derived for both the initial and the strengthened building, exploring alternative definitions of seismic damage states, including some proposals originating from recent international research programmes.

scholarly journals Relationships Between Empirical Damage and Direct/Indirect Costs for the Assessment of Seismic Loss Scenarios

2021 ◽  
Author(s):  
Marco Di Ludovico ◽  
Giuseppina De MArtino ◽  
Andrea Prota ◽  
Gaetano Manfredi ◽  
Mauro Dolce
Keyword(s):  
Empirical Data ◽  
Residential Buildings ◽  
Fragility Curves ◽  
Unit Cost ◽  
Indirect Costs ◽  
Mitigation Strategies ◽  
Damage State ◽  
Reconstruction Process ◽  
2009 L’Aquila Earthquake ◽  
Damage States

Abstract The definition of relationships between damage and losses is a crucial aspect for the prediction of seismic effects and the development of reliable models to define risk maps, loss scenarios and mitigation strategies. The paper focuses on the analysis of post-earthquake empirical data to define relationships between buildings’ damage expressed as usability rating or as global damage state and the associated costs for repair (i.e. direct costs) or for population assistance (i.e. a part of total indirect costs). The analysis refers to the data collected on residential buildings damaged by 2009 L'Aquila earthquake. For different usability rating or damage states, the paper presents the costs expressed in terms of percentage with respect to the reference unit cost of a new building (%Cr and %Ca for repair and population assistance costs, respectively). In particular, the costs analysis refers to undamaged, lightly or severely damaged buildings classified according to usability rating (i.e. A, B-C or E according to Italian classification) or to five different global Damage States (DSs). DSs comply with European Macroseismic Scale (EMS-98) and derive from literature available matrices properly defined to convert empirical damage to structural and non-structural components into building global damage. The %Cr probability density functions and relevant statistics derive from the analysis of actual data of post-earthquake reconstruction process, while, to determine those related to %Ca, a deep analysis of population assistance types, person/month assistance cost for each assistance form, and a methodology to associate such costs to each building are herein presented and discussed. Finally the paper presents a relationship calibrated on empirical data to directly correlate repair costs on a building with assistance costs to their occupants.The relationships between empirical damage and direct and indirect costs herein presented are of paramount importance because they allow reliable loss scenarios to be defined by simply using literature fragility curves (defined according to empirical or mechanical approaches) aimed at evaluating the probability of exceeding different usability rating or damage states of existing buildings.

scholarly journals Empirical fragility curves for Italian residential RC buildings

2020 ◽  
Author(s):  
A. Rosti ◽  
C. Del Gaudio ◽  
M. Rota ◽  
P. Ricci ◽  
M. Di Ludovico ◽  
...  
Keyword(s):  
Fragility Curves ◽  
National Level ◽  
Fragility Analysis ◽  
Negative Evidence ◽  
Building Height ◽  
Damage Level ◽  
Depth Analysis ◽  
Damage Data ◽  
Building Characteristics ◽  
Observed Damage

AbstractIn this paper, empirical fragility curves for reinforced concrete buildings are derived, based on post-earthquake damage data collected in the aftermath of earthquakes occurred in Italy in the period 1976–2012. These data, made available through an online platform called Da.D.O., provide information on building position, building characteristics and damage detected on different structural components. A critical review of this huge amount of data is carried out to guarantee the consistency among all the considered databases. Then, an in-depth analysis of the degree of completeness of the survey campaign is made, aiming at the identification of the Municipalities subjected to a partial survey campaign, which are discarded from fragility analysis. At the end of this stage, only the Irpinia 1980 and L’Aquila 2009 databases are considered for further elaborations, as fully complying with these criteria. The resulting database is then integrated with non-inspected buildings sited in less affected areas (assumed undamaged), to account for the negative evidence of damage. The PGA evaluated from the shakemaps of the Italian National Institute of Geophysics and Volcanology (INGV) and a metric based on six damage levels according to EMS-98 are used for fragility analysis. The damage levels are obtained from observed damage collected during post-earthquake inspections through existing conversion rules, considering damage to vertical structures and infills/partitions. The maximum damage level observed on vertical structures and infills/partitions is then associated to the whole building. Fragility curves for two vulnerability classes, C2 and D, further subdivided into three classes of building height, are obtained from those derived for specific structural typologies (identified based on building height and type of design), using their frequency of occurrence at national level as weights.

scholarly journals Seismic Vulnerability Assessment of Single-Story Masonry Buildings in Kurdistan Region - Iraq

2018 ◽  
Vol 7 (4) ◽  
pp. 18
Author(s):  
Abdulhameed A. Yaseen ◽  
Mezgeen S. Ahmed
Keyword(s):  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Seismic Loads ◽  
Seismic Zone ◽  
Kurdistan Region ◽  
Building Stock ◽  
Seismic Vulnerability Assessment ◽  
Motion Time ◽  
Damage States ◽  
Time Histories

Although the Kurdistan Region (KR) of Iraq lies in a relatively active seismic zone, most of its buildings have not been designed to resist seismic loads. So, the need to assess the vulnerability of the building stock to damage due to seismic loads will always be a demand. The building environment in the KR had extensively utilized low-rise unreinforced masonry (URM) buildings having one- to two-stories. The single-story buildings constitute about 67% of the total buildings in the region. The study aims to assess these types of buildings (single-story URM buildings) using the analytical fragility analysis approach. For that purpose, buildings in the region were classified and a typical single-story URM building was analytically modelled in TREMURI software. Seismic characteristics of KR were reviewed and based on it, 59 un-scaled ground motion time histories were selected from all parts of the world. Using incremental dynamic analysis, time histories applied to the analytical model and fragility curves were then developed for the different states of damage. The results show that the single-story buildings in the region are highly susceptible to slight and moderate damages under seismic loads; extensive as well as the very heavy damage states are likewise expected to happen in these types of buildings especially in the eastern part of the KR.

scholarly journals Usage of the Pareto Fronts as a Tool to Select Data in the Forecasting Process—A Short-Term Electric Energy Demand Forecasting Case

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3204
Author(s):  
Michał Sabat ◽  
Dariusz Baczyński
Keyword(s):  
Energy Demand ◽  
Demand Forecasting ◽  
Electric Energy ◽  
Forecasting Model ◽  
Short Term ◽  
Complex Evaluation ◽  
Proposed Model ◽  
Energy Demand Forecasting ◽  
Pareto Fronts ◽  
Naive Approach

Transmission, distribution, and micro-grid system operators are struggling with the increasing number of renewables and the changing nature of energy demand. This necessitates the use of prognostic methods based on ever shorter time series. This study depicted an attempt to develop an appropriate method by introducing a novel forecasting model based on the idea to use the Pareto fronts as a tool to select data in the forecasting process. The proposed model was implemented to forecast short-term electric energy demand in Poland using historical hourly demand values from Polish TSO. The study rather intended on implementing the range of different approaches—scenarios of Pareto fronts usage than on a complex evaluation of the obtained results. However, performance of proposed models was compared with a few benchmark forecasting models, including naïve approach, SARIMAX, kNN, and regression. For two scenarios, it has outperformed all other models by minimum 7.7%.

scholarly journals Fragility curves for Italian URM buildings based on a hybrid method

2021 ◽  
Author(s):  
A. Sandoli ◽  
G. P. Lignola ◽  
B. Calderoni ◽  
A. Prota
Keyword(s):  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Limit State ◽  
Ultimate Limit State ◽  
Masonry Building ◽  
Masonry Buildings ◽  
Seismic Behaviour ◽  
Building Stock ◽  
Ground Acceleration ◽  
Damage Scenario

AbstractA hybrid seismic fragility model for territorial-scale seismic vulnerability assessment of masonry buildings is developed and presented in this paper. The method combines expert-judgment and mechanical approaches to derive typological fragility curves for Italian residential masonry building stock. The first classifies Italian masonry buildings in five different typological classes as function of age of construction, structural typology, and seismic behaviour and damaging of buildings observed following the most severe earthquakes occurred in Italy. The second, based on numerical analyses results conducted on building prototypes, provides all the parameters necessary for developing fragility functions. Peak-Ground Acceleration (PGA) at Ultimate Limit State attainable by each building’s class has been chosen as an Intensity Measure to represent fragility curves: three types of curve have been developed, each referred to mean, maximum and minimum value of PGAs defined for each building class. To represent the expected damage scenario for increasing earthquake intensities, a correlation between PGAs and Mercalli-Cancani-Sieber macroseismic intensity scale has been used and the corresponding fragility curves developed. Results show that the proposed building’s classes are representative of the Italian masonry building stock and that fragility curves are effective for predicting both seismic vulnerability and expected damage scenarios for seismic-prone areas. Finally, the fragility curves have been compared with empirical curves obtained through a macroseismic approach on Italian masonry buildings available in literature, underlining the differences between the methods.

scholarly journals A Phenomenological Primary–Secondary–Tertiary Creep Model for Polymer-Bonded Composite Materials

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2353
Author(s):  
Xiaochang Duan ◽  
Hongwei Yuan ◽  
Wei Tang ◽  
Jingjing He ◽  
Xuefei Guan
Keyword(s):  
Composite Materials ◽  
Creep Behavior ◽  
Reference Model ◽  
Creep Model ◽  
Creep Process ◽  
Validation Dataset ◽  
Testing Conditions ◽  
Proposed Model ◽  
Testing Data ◽  
Bonded Composite

This study develops a unified phenomenological creep model for polymer-bonded composite materials, allowing for predicting the creep behavior in the three creep stages, namely the primary, the secondary, and the tertiary stages under sustained compressive stresses. Creep testing is performed using material specimens under several conditions with a temperature range of 20 °C–50 °C and a compressive stress range of 15 MPa–25 MPa. The testing data reveal that the strain rate–time response exhibits the transient, steady, and unstable stages under each of the testing conditions. A rational function-based creep rate equation is proposed to describe the full creep behavior under each of the testing conditions. By further correlating the resulting model parameters with temperature and stress and developing a Larson–Miller parameter-based rupture time prediction model, a unified phenomenological model is established. An independent validation dataset and third-party testing data are used to verify the effectiveness and accuracy of the proposed model. The performance of the proposed model is compared with that of an existing reference model. The verification and comparison results show that the model can describe all the three stages of the creep process, and the proposed model outperforms the reference model by yielding 28.5% smaller root mean squared errors on average.

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