1,721,009 research outputs found
Loss assessment models for seismic risk mitigation in structures
Full text linkSeismic risk can be defined as an inclusive term that encompasses the probability of different ground motions and the related consequences, depending on the structural vulnerability. Seismic risk analysis is a general procedure that usually can consider different indicators, for both a specific structure or at territorial level: among others, for civil structures, risk is expressed in terms of monetary losses, i.e. costs to be sustained for repairing seismic damage or loss of revenue. This work wants to contribute to the current seismic risk assessment approaches with original contributions to the analysis of both point-like and territorial assets, focusing on some aspects, that are still not or poorly treated in literature. Regarding seismic risk analysis for a single specific structure, this work focuses on seismic risk analysis of industrial productive processes, with particular reference to business interruption losses. Recent seismic events, as the Emilia-Romagna earthquake in 2012, showed that such type of indirect losses can be very significant, and therefore a model is proposed to fill this lack of models for assessing indirect losses due to business interruption. Furthermore, a financial framework is also set up to assess the optimal seismic retrofit strategy for productive processes. In regard to the seismic risk analysis at territorial level, a seismic risk map of Italy is developed. Some considerations on historical losses and the implementation of specific earthquake catastrophe funds is also discussed. Finally, a deep insight on Catastrophe bonds (CAT bonds), as financial tool for transferring potential losses arising from natural hazards is illustrated. In particular, a novel reliability-based CAT bond pricing framework is developed, and applied to a case study represented by the Italian residential building portfolio
A framework for assessing the seismic risk map of Italy and developing a sustainable risk reduction program
No full textThis work proposes a framework for the development of seismic risk maps at the nationwide scale. The seismic risk map is computed taking into account a seismogenic model of the analyzed area, and properly characterizing vulnerability and exposure of an asset of interest. A risk-targeted indicator named Municipal Expected Annual Loss (MEAL) is introduced and used as suitable metric for the development of the map, and for the subsequent seismic risk rating. The framework is then applied to show its usefulness in order to derive the seismic risk map of Italy considering the residential building stock as asset of interest. The proposed scientific approach for mapping seismic risk can be further used to develop a seismic risk reduction program and then evaluating its financial sustainability. The final part of the paper shows therefore a hypothetical seismic risk reduction program for the Italian residential building stock, estimating costs, benefits, and time-intervals required to guarantee its financial sustainability with the introduction of different taxation scenarios
Experimental and numerical study of the cyclic behavior of exterior RC beam-column joints made with recycled concrete
No full textAn experimental and numerical investigation about exterior reinforced beam-column joints made with recycled concrete, and subject to horizontal reversed cyclic loading, is shown in this paper. Three real scale RC joints were casted with electric arc furnace slag as recycled coarse aggregate, and then tested under quasi-static cyclic loading, to study the influence of this kind of “green concrete” on the global behavior of the specimens. Particularly, ultimate load, hysteresis response and dissipated energy were analyzed. The joints exhibited the same failure mode, which involved the shear failure of panel joint and yielding of beam steel longitudinal bars: this kind of failure is indeed the most influenced by concrete properties. Then a numerical investigation was carried out, consisting of three- dimensional nonlinear finite element (FE) models, which were validated with the experimental results. Lastly, a parametric study was carried out to understand the effects of column axial load, beam longitudinal reinforcement bar amount and column transverse reinforcement ratio. Results indicate that, in all the analyzed cases, the seismic performance of the joints made with EAF slag concrete at least comparable than with conventional material
Reversible ground motion-to-intensity conversion equations based on the EMS-98 scale
No full textThe relation between observed macroseismic intensities and recorded ground motion parameters is a matter of interest in earthquake engineering, and it has been widely discussed in literature in the past. Several relationships already exist, correlating macroseismic intensity and peak ground motion parameters (i.e. PGA, PGV or PGD, respectively peak ground acceleration, velocity and displacement). However, most of these formulations are based on Mercalli-Cancani-Sieberg (MCS) scale, developed using regional databases and difficult to be applied at large scale. In this research, new formulations are proposed that correlate European Macroseismic Scale (EMS-98) with ground shaking parameters (PGMs), Arias intensity and Housner intensity. An initial PGM/EMS-98 intensity dataset was assembled for this scope, collecting 610 data pairs of observations, from 35 different Italian seismic events derived from the Parametric Catalogue of Italian Earthquakes (CPTI15) and the Italian Accelerometric Archive (ITACA), subsequently filtered considering only tectonic events and data pairs with site – station distances lower than 3 km. The resulting final dataset of 220 data pairs from 22 earthquakes was thus used to obtain regression relationships, finally compared with existing models based on the Modified Mercalli (MM) scale and MCS scale
Damage Scenario and Economic Losses Estimation of Historical Earthquakes Occurred in Northeastern Italy
No full textThis study aims to assess the potential economic losses that will be cause nowadays by the historical earthquakes occurred in the past in Northeastern Italy. This area of the country, even if seismically calm in the recent past, has been struck by several significant earthquakes in the last centuries. For this reason, a review of the main historical earthquakes is herein presented, together with an analysis of the residential building stock aimed at developing a suitable taxonomy class for the definition of the structural vulnerability. Since that for the analyzed events no shake-maps were available, part of the work was dedicated to the development of a shaking scenario engine able to reproduce some recent Italian Earthquakes. Results showthat Northeastern Italy is particularly susceptible of significant economic losses, due to its high urbanization and high structures’ vulnerability. Furthermore, economical losses can be amplify considering the fact the area of study is particularly industrialized. The presentedwork has been developed within the Interreg Crossit Safer European Project
Building damage assessment after the Riviera del Brenta tornado, northeast Italy
No full textA tornado with severe intensity hit the municipalities of Pianiga, Dolo and Mira close to Venice, northeast Italy, causing damages on a wide number of residential and industrial buildings and destroying some historical villas. In this study, the authors show the results of the damage assessment survey performed in the first days after the occurrence of the extreme event. Limited literature deals with damage assessment of European building types due to wind actions, and the available one does not consider building vulnerability as key factor in the structural response of existing structures subject to tornado hazard. In this paper, structural damages surveyed in reinforced concrete frame structures and masonry buildings, representative of common Italian building types, are critically discussed. Additionally, this work provides a database of past tornado events in northeast Italy, evidencing how the analyzed area has been found to be quite prone to tornado hazard
Demolition waste management after recent Italian earthquakes
No full textThis work compares the disaster waste management policies carried out in Italy, after two recent earthquakes (Mw 6.3 L’Aquila; Mw 5.86 Emilia-Romagna) and the Mw 6.46 1976 Friuli earthquake. Special attention is paid on the positive experience of building waste management in the town of Venzone, Friuli-Venezia Giulia (north-eastern Italy), which historic buildings were almost completely damaged. Indeed, it is possible to recognize that, more than 40 years after that event, the recycling program conducted by the Municipality allowed to fully recover the cultural heritage; additionally, this choice avoided significant environmental impacts, considering the alternative forms of disaster waste disposal
Analysis of the 2016 Amatrice earthquake macroseismic data
Full text linkOn August 24, 2016, a sudden MW 6.0 seismic event hit Central Italy, causing 298 victims and significant damage to residential buildings and cultural heritage. In the days following the mainshock, a macroseismic survey was conducted by teams of the University of Padova, according to the European Macroseismic Scale (EMS98). In this contribution, a critical analysis of the collected macroseismic data is presented and some comparisons were performed with the recent 2012 Emilia sequence
Reliability-based analysis of recycled aggregate concrete under carbonation
Full text linkDurability represents a crucial issue for evaluating safety and serviceability of reinforced concrete structures. Many studies have already focused on carbonation-induced corrosion of natural aggregate concrete (NAC) structures, leading to several prediction models to estimate carbonation depth. Less research is devoted instead on recycled aggregate concrete (RAC), about which limited experimental works exist aimed at assessing the carbonation coefficient in accelerated tests. Additionally, deteriorating processes are subject to uncertainty, when defining materials, geometry, and environmental actions during the service life of structures. This work presents a reliability-based analysis of carbonation resistance of RACs, using experimental carbonation coefficients derived from the literature, and applied in the full-probabilistic method prosed in fib Bulletin 34. Results demonstrate how aggregates replacement ratio and w/c ratio influence the reliability of RAC carbonation resistance
- …
