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Lauzacco, Italy

Calvi G.M.,IUSS Pavia | Sullivan T.J.,University of Pavia | Welch D.P.,ROSE Programme
Geotechnical, Geological and Earthquake Engineering | Year: 2014

Several performance measures are being used in modern seismic engineering applications, suggesting that seismic performance could be classified a number of ways. This paper reviews a range of performance measures currently being adopted and then proposes a new seismic performance classification framework based on expected annual losses (EAL). The motivation for an EAL-based performance framework stems from the observation that, in addition to limiting lives lost during earthquakes, changes are needed to improve the resilience of our societies, and it is proposed that increased resilience in developed countries could be achieved by limiting monetary losses. In order to set suitable preliminary values of EAL for performance classification, values of EAL reported in the literature are reviewed. Uncertainties in current EAL estimates are discussed and then an EAL-based seismic performance classification framework is proposed. The proposal is made that the EAL should be computed on a storey-by-storey basis in recognition that EAL for different storeys of a building could vary significantly and also recognizing that a single building may have multiple owners. A number of tools for the estimation of EAL are reviewed in this paper and the argument is made that simplified methods for the prediction of EAL are required as engineers transition to this new performance parameter. In order to illustrate the potential value of an EAL-based classification scheme, a three storey RC frame building is examined using a simplified displacement-based loss assessment procedure and performance classifications are made for three different retrofit options. The results show that even if only limited non-structural interventions are made to the case study, the EAL could be significantly reduced. It is also argued that overall, such a performance classification, coupled with some form of government or insurance-driven incentive scheme, may provide an effective means of reducing the risk, and increasing the resilience, of our societies. © The Author(s) 2014.

Milanesi R.R.,IUSS Pavia | Morandi P.,University of Pavia | Magenes G.,University of Pavia | Binici B.,Middle East Technical University
COMPDYN 2015 - 5th ECCOMAS Thematic Conference on Computational Methods in Structural Dynamics and Earthquake Engineering | Year: 2015

Unreinforced masonry non-structural infills in RC structures are widely used in many countries. However, they are often designed with simplified methods which do not consider accurately their interaction with the structure. The limitation of their damage induced by earthquakes is of major interest for the prevention of extensive economic losses and possible threats to human lives. During the last decades several researches have been accomplished all around the world, and many different aspects have been investigated. The increasing interest on masonry infill is due to both the observation of unsatisfactory behaviour of infilled frame structures after real earthquakes and the difficulty to reach a widely scientifically recognized solution. Even if measures for the prevention of infill damage are to some extent included in modern seismic design code, an effective design procedure has not yet been achieved. The object of this study is to perform a numerical Finite Element Model simulation of a reinforced concrete frame specimen infilled with unreinforced Autoclaved Aerated Concrete masonry infill, in order to be able to study accurately the influence and the interaction of the non-structural wall to the reinforced concrete frame. A meso-modelling approach has been followed and the calibration has been performed according to the results of in-plane cyclic tests on single bay - single storey bare and infilled frames which have been carried out at the Department of Civil Engineering and Architecture of the University of Pavia [1, 3]. In order to obtain the parameters of the infill material, the numerical simulation has been performed, in first instance, with reference to tests of mechanical characterization and to inplane cyclic tests on load-bearing AAC masonry, similar to the one used for the infill [2, 3]. The model has been validated via non-linear static analyses. Moreover, the change in moment and shear demands on the RC members of the frame due to the influence of the presence of the infill as respect to the bare frame condition has also been investigated.

De Luca A.,Istituto di Astrofisica Spaziale e Fisica Cosmica | Salvaterra R.,Istituto di Astrofisica Spaziale e Fisica Cosmica | Tiengo A.,IUSS Pavia | D'Agostino D.,CNR Institute for Applied Mathematics and Information Technologies | And 3 more authors.
Astrophysics and Space Science Proceedings | Year: 2016

The EXTraS project (“Exploring the X-ray Transient and variable Sky”) will characterise the temporal behaviour of the largest ever sample of objects in the soft X-ray range (0.1–12 keV) with a complex, systematic and consistent analysis of all data collected by the European Photon Imaging Camera (EPIC) instrument onboard the ESA XMM-Newton X-ray observatory since its launch.We will search for, and characterize variability (both periodic and aperiodic) in hundreds of thousands of sources spanning more than nine orders of magnitude in time scale and six orders of magnitude in flux. We will also search for fast transients, missed by standard image analysis. Our analysis will be completed by multiwavelength characterization of new discoveries and phenomenological classification of variable sources. All results and productswill be made available to the community in a public archive, serving as a reference for a broad range of astrophysical investigations. © Springer International Publishing Switzerland 2016.

Sullivan T.J.,University of Pavia | Sullivan T.J.,European Center for Training and Research in Earthquake Engineering | Welch D.P.,UME School | Calvi G.M.,IUSS Pavia
Earthquake Engineering and Engineering Vibration | Year: 2014

The last decade or so has seen the development of refined performance-based earthquake engineering (PBEE) approaches that now provide a framework for estimation of a range of important decision variables, such as repair costs, repair time and number of casualties. This paper reviews current tools for PBEE, including the PACT software, and examines the possibility of extending the innovative displacement-based assessment approach as a simplified structural analysis option for performance assessment. Details of the displacement-based s+eismic assessment method are reviewed and a simple means of quickly assessing multiple hazard levels is proposed. Furthermore, proposals for a simple definition of collapse fragility and relations between equivalent single-degree-of-freedom characteristics and multi-degree-of-freedom story drift and floor acceleration demands are discussed, highlighting needs for future research. To illustrate the potential of the methodology, performance measures obtained from the simplified method are compared with those computed using the results of incremental dynamic analyses within the PEER performance-based earthquake engineering framework, applied to a benchmark building. The comparison illustrates that the simplified method could be a very effective conceptual seismic design tool. The advantages and disadvantages of the simplified approach are discussed and potential implications of advanced seismic performance assessments for conceptual seismic design are highlighted through examination of different case study scenarios including different structural configurations.

Welch D.P.,ROSE Programme | Sullivan T.J.,University of Pavia | Calvi G.M.,IUSS Pavia
Journal of Earthquake Engineering | Year: 2014

Various loss assessment methodologies have been proposed and developed over the past decades to provide risk assessment on a regional scale. There is an increasing need, however, to provide engineers with practical tools for building-specific loss assessment. Recently, progress has been made towards probabilistic loss models such as the PEER framework. However, as comprehensive probabilistic methodologies could be too complex for practicing engineers, this article presents a simplified probabilistic loss assessment methodology that builds on a direct displacement-based framework. The methodology is tested via examination of two RC frame buildings and encouragingly shows similar results to the PEER methodology. © 2014 Copyright A. S. Elnashai.

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