Pandolfi, Francesco (2022) Performance-based wind risk assessment: computational tools for a building-component oriented vulnerability approach. [Tesi di dottorato]

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Item Type: Tesi di dottorato
Resource language: Italiano
Title: Performance-based wind risk assessment: computational tools for a building-component oriented vulnerability approach
Creators:
CreatorsEmail
Pandolfi, Francescofrancesco.pandolfi@unina.it
Date: 10 March 2022
Number of Pages: 255
Institution: Università degli Studi di Napoli Federico II
Department: Strutture per l'Ingegneria e l'Architettura
Dottorato: Ingegneria strutturale geotecnica e rischio sismico
Ciclo di dottorato: 34
Coordinatore del Corso di dottorato:
nomeemail
Iervolino, Iunioiunio.iervolino@unina.it
Tutor:
nomeemail
Iervolino, Iunioiunio.iervolino@unina.it
Date: 10 March 2022
Number of Pages: 255
Keywords: extreme wind; probabilistic risk assessment; component wind fragility; vulnerability model; wind-induced losses; computer-aided risk assessment.
Settori scientifico-disciplinari del MIUR: Area 08 - Ingegneria civile e Architettura > ICAR/09 - Tecnica delle costruzioni
Date Deposited: 30 Sep 2022 07:02
Last Modified: 30 Sep 2022 07:02
URI: http://www.fedoa.unina.it/id/eprint/13433

Collection description

The impact of extreme winds on industrial assets and the built environment is gaining increasing attention from stakeholders, including the corporate insurance industry. This has led to a progressively more in-depth study of building vulnerability and fragility to wind. Wind vulnerability models are used in probabilistic risk assessment, to relate a loss metric to an intensity measure of the natural event, in this case usually a gust or mean wind speed. In fact, vulnerability models can be integrated with wind hazard to provide an assessment of future losses due to extreme wind. Wind hazard on the other hand, can be quantified by associating a probability to the exceedance of each intensity level within a time interval which has been the objective of world- and regional-scale wind hazard studies. One approach often adopted for the probabilistic description of building vulnerability to wind, is the use of fragility functions, which provide the conditional probability that selected building components will exceed certain damage states, given wind intensity. In fact, in wind engineering literature, it is more common to find structural system- or component-level fragility functions, rather than wind vulnerability models for an entire building. In this context, models for assessing the vulnerability and fragility of structures to wind and their historical evolution over the last 50 years were investigated. On this basis it was possible to identify the fundamental characteristics in the assessment of the vulnerability of structures to wind. Among these, the importance of the relationships between the failures of different components of the structure emerged. Loss assessment based on component fragility requires some logical combination rules that define the building’s damage state given the damage state of each component, and the availability of a consequence model that provides the losses associated to each damage state. In state-of-the-art risk calculations, which are based on numerical simulation of a structure’s behavior during extreme wind scenarios, the interaction of component damage is intertwined with the computational procedure. Since simulation-based approaches are usually computationally demanding and case-specific, an approach for the composition of a fragility function for the entire structure, using available component fragilities, is developed and discussed in this thesis. This procedure also involves the development of a database containing a large number of recent and past vulnerability studies. The heterogeneity of models found in the literature also promoted a search for vulnerability function conversion methods. All these features have been integrated in the \textit{ExtReMe wind risk assESsment prototype Software, ERMESS}, an ad-hoc developed wind risk assessment tool for insurance applications, based on in-built or user-defined wind hazard data. Collecting a wide assortment of available wind vulnerability models and fragility functions, this software implements also the previously introduced alternative method for building-specific risk assessment based on existing component-level fragility functions and on a number of simplifying assumptions for their interactions. The applicability of ERMESS's output has been validated and, despite the simplifying assumptions, the procedure can yield evaluations that are comparable to those obtained via more rigorous building-level simulation-based methods, at least in the considered examples. The advantage of this approach lies in the fact that a database of building component fragility curves can be put to use for the development of new wind vulnerability models to cover building typologies not yet adequately covered by existing works and whose rigorous development is usually beyond the budget of portfolio-related industrial applications.

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