1,721,067 research outputs found
The role of reinforced concrete roofs in the seismic performance of masonry buildings
Full text linkThe 2016 Central Italy earthquake caused many collapses of existing masonry buildings that had previously been retrofitted with reinforced concrete roofs. The aim of this paper is to explore the role of these roofs in the seismic behaviour of masonry buildings. Simple analytical models are presented to illustrate two typical out-of-plane collapse mechanisms: wall overturning and vertical flexure. The models are based on linear kinematic analysis, which allows fast modelling and calculation of a coefficient that can be used to assess the safety level of a structure. Nonlinear kinematic analyses were also performed. Both methods were applied to two case studies taken from areas struck by the earthquake. Results show that linear analysis represents an effective tool for preliminary verifications that can allow one to understand whether retrofit interventions are needed
Metrics for evaluating the seismic vulnerability of telecommunication networksE
Full text linkUrban communities have been massively relying on telecommunication infrastructures for everyday activities in the past decade. Their importance is also crucial during emergencies to enable communication among users and first responders. This paper presents a methodology to model and assess the seismic vulnerability of wireless telecommunication networks on the urban scale. The case study is a virtual testbed that is representative of a typical European city. The information to model the infrastructure has been collected from a crowdsourced database and satellite imagery. Since most of the telecommunication network components are located on the roof and inside buildings, the vulnerability of the network has been linked to the damages caused by a given earthquake scenario to the built environment. Different simulations allowed to estimate the failed towers, the available throughput, and the number of users served by each base station after the seismic event. These results have been used to formulate three vulnerability metrics that can be used for detailed resilience analyses
State-of-the-Art of Resilience Using Bibliometric Analysis
Full text linkThe interest in the concept of Resilience in the scientific community has been growing consistently over the past few years to study the functionality and behavior of systems against natural and man-made hazards. This is reflected by the number of journal articles that can be accessed in the Web of Science database. In this paper, a bibliometric and visualization method is applied to explore the status of resilience research in civil engineering applications by analyzing the journal papers published from 1996 to 2020. The bibliometric analysis aims at consolidating the state of the art by identifying influential journals, most cited articles, the geographic distribution of resilience publications including the research institutions by country, the author keywords distribution, and the co-authorship status. The concept of resilience is investigated through eight subject categories identified by the authors in the literature: Recovery time strategies and Downtime, Critical infrastructures, Probabilistic approaches, Fuzzy logic approaches, Structural health monitoring, Health Care facilities, Emergency management and Decision-making, Community and Urban Resilience. Results show that resilience research has increased rapidly since its introduction, most notably in the last seven years. In terms of the geographical region of the studies, most of them have been carried out in the USA, the United Kingdom, China, and Italy. Finally, based on the author keywords analysis, it is possible to observe that recovery strategies, critical infrastructures, vulnerability, and community resilience have attracted prominent attention during the past decade
Collaborazioni interaziendali e reti di impresa nella riconfigurazione strategica del sistema economico-sociale: luci, ombre e sfide per il futuro
No full textSEISMIC VULNERABILITY ASSESSMENT OF AN URBAN NATURAL GAS NETWORK
Full text linkNatural and man-made hazards have shown that modern societies are heavily dependent on critical infrastructures. The natural gas network plays a key role in a community economy, and seismic events might be detrimental for its safety and wellness. This paper proposes a methodology to assess the seismic vulnerability of urban natural gas networks. A physical-based model of the network of a virtual city has been developed. The modeling and calibration have been executed using a Python simulation tool. The model has then been used to evaluate the damage induced by the ground shaking and permanent soil deformation caused by a given seismic scenario. Network damage has been estimated in terms of gas leaks and pipe breaks. The methodology provides an effective tool to measure vulnerability and identify the critical components of the network. The results of the analysis can be used to assess the resilience of the gas infrastructure and to implement strategies for improving the overall community resilience
Automating the Frequency Domain Decomposition Technique Using the Modal Assurance Criterion
No full textInfrastructures are degrading rapidly, which necessitates the application of automated dynamic characterization in damage identification schemes. The Operational Modal Analysis (OMA) is an effective tool to process monitoring data of structural assets. In this study, the Frequency Domain Decomposition (FDD) technique is automated based on two different criteria, the Discrimination Factor (DF) and Modal Assurance Criterion (MAC). The recorded ambient vibration response of a cable-stayed bridge was used as input to the proposed method to extract its modal properties automatically. The method was also tested on a calibrated finite element model of the cable-stayed bridge for validation purposes. The optimal automation performance is achieved by establishing the best range of each criterion
Managing debris clearance from road transportation networks after earthquakes
Full text linkThis research proposes a framework that allows to define a debris removal strategy from a road transportation network after a seismic event. The case study is a hypothetical large-scale city consisting of many interdependent infrastructure. Once the debris generated by the collapse of buildings have been estimated, blocked roads are identified. Cleanup operations are then prioritized based on road importance and travel time. The goal is to first verify that evacuation routes and important paths connecting strategic facilities such as hospitals, shelters, fire stations, etc., are available. In case some roads within these paths are blocked, alternative routes are considered. If the pre-event travel time does not significantly increase, clearing equipment and resources could be managed accordingly and directed towards other areas. The objective of this work is to help emergency managers to successfully improve disaster response avoiding delays during rescue and recovery operations
La Storia della Perugina (1907 - 1985). La vicenda imprenditoriale attraverso l'analisi dei bilanci societari - Dalla rilevazione contabile all'economia aziendale
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