262 research outputs found

    On the simulation of the seismic energy transmission mechanisms

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    In recent years, considerable attention has been paid to research and development methods able to assess the seismic energy propagation on the territory. The seismic energy propagation is strongly related to the complexity of the source and it is affected by the attenuation and the scattering effects along the path. Thus, the effect of the earthquake is the result of a complex interaction between the signal emitted by the source and the propagation effects. The purpose of this work is to develop a methodology able to reproduce the propagation law of seismic energy, hypothesizing the "transmission" mechanisms that preside over the distribution of seismic effects on the territory, by means of a structural optimization process with a predetermined energy distribution. Briefly, the approach, based on a deterministic physical model, determines an objective correction of the detected distributions of seismic intensity on the soil, forcing the compatibility of the observed data with the physical-mechanical model. It is based on two hypotheses: (1) the earthquake at the epicentre is simulated by means of a system of distortions split into three parameters; (2) the intensity is considered coincident to the density of elastic energy. The optimal distribution of the beams stiffness is achieved, by reducing the difference between the values of intensity distribution computed on the mesh and those observed during four regional events historically reported concerning the Campania region (Italy)

    Theoretical model for cascading effects analyses

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    Abstract In case of exceptional events of natural or anthropogenic type, the elements at risk (people, buildings, infrastructures, economy, etc.) are often hit by sequences of 'cascading events', function of time and space, caused by the triggering event (earthquake, landslide, volcanic eruption, fire, electric failure, etc.). Generally, sequences of events can involve the same element at risk, and the combined effects of cascading phenomena can strongly amplify the impact caused by single events in terms of extension of the affected area and damage level. The final impact on the territory can be significant and require to be carefully assessed in terms of emergency planning and management. This paper discusses from a theoretical point of view the modelling needs and the main issues to be taken into account in the development of simulation tools aiming to include cascading effects analyses to effectively support decision-makers in their preparedness and disaster mitigation strategies in the framework of emergency planning at local, national and international level. The model aims at developing cascading effects scenarios at different level of detail, depending on the availability of inventory/exposure data for the different categories of elements at risk and hazard/impact models for the various hazard sources. It has been developed within EU-FP7 SNOWBALL project (Lower the impact of aggravating factors in crisis situations thanks to adaptive foresight and decision-support tools, 2015–2017)

    Analysis of Ordinary Buildings on the Island of Ischia (Italy) for a Seismic Impact Assessment

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    Ischia is a quiescent volcanic complex, characterized by several periods of activity, also of explosive typology. Each year, seismic stations detect few low-energy events, although in the past severe earthquakes occurred, causing extensive damage. The last significant seismic event, with a magnitude of 3.91, occurred on 21st August 2017, again in the municipality of Casamicciola. The hazard constituted by seismic phenomena is compounded by a high exposed value, in terms of population and buildings. From 1861 to today, the resident population has increased considerably, from 23,511 to 62,831 units, to which are added 4 million tourists a year. The high risk of the Ischia territory highlights the need to bring the sustainable planning at the centre of the debate, considering the vulnerability of the area. In this perspective, an application aimed at assessing the seismic impact scenario induced by a single seismic event is illustrated below. The aim is to show a methodological approach able to quantify the resources necessary for emergency planning and organization of operational intervention

    Multicriteria Fuzzy Analysis for a GIS-Based Management of Earthquake Scenarios

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    Objective of this article is the formulation andthe implementation of a decision-making model for theoptimal management of emergencies. It is based on theaccurate definition of possible scenarios resulting fromprediction and prevention strategies and explicitly takesinto account the subjectivity of the judgments of prefer-ence. To this end, a multicriteria decision model, basedon fuzzy logic, has been implemented in a user-friendlygeographical information system (GIS) platform so asto allow for the automation of choice processes betweenseveral alternatives for the spatial location of the investi-gated scenarios. In particular, we have analyzed the po-tentialities of the proposed approach in terms of seismicrisk reduction, simplifying the decision process leadingto the actions to be taken from directors and managers ofcoordination services. Due to the large number of vari-ables involved in the decision process, it has been pro-posed a particularly flexible and streamlined method inwhich the damage scenarios, based on the vulnerabilityof the territory, have represented the input data to de-rive a vector of weights to be assigned to different de-cision alternatives. As an application of the proposedapproach, the seismic damage scenario of a region of400 km2, hit by the 2009 earthquake in L’Aquila (Italy),has been analyzed

    Building Inventory at National scale by evaluation of seismic vulnerability classes distribution based on Census data analysis: BINC procedure

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    In this paper, the BINC procedure (Building Inventory at National scale based on Census data) is proposed. It is a quick methodology to assess the building inventory needed to seismic exposure assessment at regional and national scale. Vulnerability classes map for the whole Italian region is proposed. BINC procedure, developed at the PLINIVS Study Centre (University of Naples Federico II), is able to provide a seismic vulnerability assessment on the basis of 'weak' data. The information used to set the method are carried out from census database furnished by Italian National Institute of Statistics, ISTAT (DB_Census) and the da- tabase of information collected in situ by PLINIVS (DB_PLINIVS). In particular, exploiting vulnerability classes information of the DB_PLINIVS and common characteristics of the two databases, a generalization of buildings distribution on the vulnerability classes in obtained at regional national scale. The methodology can be easily extended to all countries having census data on buildings

    Empirical vulnerability curves for Italian mansory buildings: evolution of vulnerability model from the DPM to curves as a function of accelertion

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    AbstractIn the framework of the emergency management in the case of seismic events, the evaluation of the expected damage represents a basic requirement for risk informed planning. Seismic risk is defined by the probability to reach a level of damage on given exposed elements caused by seismic events occurring in a fixed period and in a fixed area. To this purpose, the expected seismic input, the exposed elements and their vulnerability have to be correctly evaluated. The aim of the research is to define a correct model of vulnerability curves, in PGA, for masonry structures in Italy, by heuristic approach starting from damage probability matrices (DPMs). To this purpose, the PLINIVS database, containing data on major Italian seismic events, has been used and supported by "critical" assumption on missing data. To support the reliability of this assumption, two vulnerability models, considering or not the hypothesis on the missing data, have been estimated and used to calculate the seismic scenario of the L'Aquila 2009 earthquake through the IRMA (Italian Risk MAp) platform. Finally, a comparison between the outcomes elaborated by IRMA platform and the observed damage collected in the AEDES forms, has been done

    Il settore delle società di progettazione e design industriale in Italia

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    Indice: Cosa è il design industriale - Il settore del design industriale - Caratteristiche generali del settore - Car design, un business a part

    Strength hierarchy provisions for transverse confinement systems of shell structural elements

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    Through-the-thickness (TT) confinement of masonry and concrete panels by composite or steel reinforcements, aiming at seismic retrofit of existing structures, has recently growth in popularity. However, structural design of transversal reinforcements, modeled as an homogeneized material, is often performed by neglecting the cyclic nature of seismic actions and by using static approaches. For this reason, a proper strength hierarchy between the confined core material and the confining devices should be accounted for in order to ensure that the retrofit system remains effective until the crisis of the core material is attained. This research introduces strength hierarchy conditions for TT-confinement systems, made of materials exhibiting a nonlinear behavior, aiming at determining the minimum strength required for uniaxial confining devices. The relevant relationships, theoretically derived by assuming a Drucker Prager constitutive model for the confined material and by enforcing equilibrium and compatibility conditions between the core and the confining devices, are characterized by simple mechanical parameters, usually available in common practice applications, familiar to most of the designers. Numerical examples confirm the effectiveness of the proposed provisions

    Farmers’ Markets, Producer and Consumer Behaviour: Analysis of Interactions with the Metrics of Sustainability

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    This paper provides insights of the Italian farmers' markets (FMs) experience. These short food chains can be conceptualized among the so-called "alternative agro-food networks", which reject the traditional food chains features - productivity, products standardization and industrial organization - to focus on other issues such as quality, local production and "naturality" of agro-food production.The main objective of the paper is to evaluate the sustainability of FMs, through the analysis of the demand and the supply side. The analysis is based on a survey administered in 13 Italian FMs, involving 158 farmers and 458 consumers. Data are used to evaluate consumers' demand for sustainability within FMs and sustainability indicators at the farm level. These indicators support a classification of the farms, aimed at analysing their motivation to participate in the markets and the extent to which they are able to meet consumers' demand.Results show that FMs might be able to favour the spreading of a more sustainable economy. However, farms should improve their business strategies in order to meet consumers' demand for sustainability. In this respect, agricultural policies at the European and local level can play a role, in order to enhance sustainable practices within the farms

    CAESAR II Tool: Complementary Analyses for Emergency Planning Based on Seismic Risks Impact Evaluations

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    Italy is a country with high seismic hazard, however since the delay in the seismic classification of the national territory, most of the existing building heritage does not comply with the current technical standards for buildings. The seismic events that have hit different Italian regions in recent years have highlighted the complexity of the challenge for the public bodies both in the emergency management and post‐event reconstruction and in the planning of effective risk prevention and mitigation measures to be implemented in ‘peacetime’. These difficulties concern, in particular, the capacity to properly manage the financial and technical resources available and to identify the intervention priorities throughout the entire emergency cycle. For correct management, the priority is to quantify and localize, through simulations, the quantification of probable damages and to evaluate in terms of cost‐benefits the possible alternative strategies for mitigation, also taking into account the potential, in terms of cost‐effectiveness, of integrated measures for seismic and energy retrofitting. In this framework, the project CAESAR II (Complementary Analyses for Emergency planning based on Seismic Risks impact evaluations) has been developed as a Decision Support System for Public Authorities in charge of developing Disaster Risk Reduction plans, with the possibility of programming mid to long‐term investments for public and private properties, as well as defining custom financial support mechanisms and tax incentives
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