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Aging considerations in the development of time-dependent seismic fragility curves / Jayadipta Ghosh in Journal of structural engineering, Vol. 136 N° 12 (Décembre 2010) 

Public ISBD [article]  in Journal of structural engineering > Vol. 136 N° 12 (Décembre 2010) . - pp. 1497-1511 Titre : Aging considerations in the development of time-dependent seismic fragility curves Type de document : texte imprimé Auteurs : Jayadipta Ghosh, Auteur ; Jamie E. Padgett, Auteur Année de publication : 2011 Article en page(s) : pp. 1497-1511 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Bridges  Seismic  Deterioration  Corrosion  Probability  Fragility Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : This paper presents the formulation of a time-dependent seismic fragility format for bridges, as well as new insights into the potential effects of aging and deterioration on seismic vulnerability traditionally neglected in fragility modeling, including joint impacts of multiple component deterioration not investigated to date. The study evaluates the impact of lifetime exposure to chlorides from deicing salts on the seismic performance of multispan continuous highway bridges, considering corrosion of reinforced concrete columns and steel bridge bearings. The components’ degradation and their influence on seismic response are illustrated through three-dimensional nonlinear dynamic analysis. A full probabilistic analysis accounting for variation in bridge, ground motion, and corrosion parameters is conducted to develop time-dependent seismic fragility curves. These fragility curves indicate the evolving potential for component and system damage under seismic loading considering time-dependent corrosion-induced deterioration. The results indicate that while corrosion may actually decrease the seismic vulnerability of some components, most critical components suffer an increase in vulnerability. Quadratic models depicting the change in lognormal seismic fragility parameters are proposed to capture the time-dependent effect of aging on the fragility of the bridge system. Overall, the seismic vulnerability significantly increases throughout the lifetime of the representative bridge geometry, with a 32% shift in the median value of complete damage fragility near the end of the bridge’s life. DEWEY : 624.17 ISSN : 0733-9445 En ligne : http://ascelibrary.org/sto/resource/1/jsendh/v136/i12/p1497_s1?isAuthorized=no [article] Aging considerations in the development of time-dependent seismic fragility curves [texte imprimé] / Jayadipta Ghosh, Auteur ; Jamie E. Padgett, Auteur . - 2011 . - pp. 1497-1511. Génie Civil Langues : Anglais (eng) in Journal of structural engineering > Vol. 136 N° 12 (Décembre 2010) . - pp. 1497-1511 Mots-clés : Bridges  Seismic  Deterioration  Corrosion  Probability  Fragility Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : This paper presents the formulation of a time-dependent seismic fragility format for bridges, as well as new insights into the potential effects of aging and deterioration on seismic vulnerability traditionally neglected in fragility modeling, including joint impacts of multiple component deterioration not investigated to date. The study evaluates the impact of lifetime exposure to chlorides from deicing salts on the seismic performance of multispan continuous highway bridges, considering corrosion of reinforced concrete columns and steel bridge bearings. The components’ degradation and their influence on seismic response are illustrated through three-dimensional nonlinear dynamic analysis. A full probabilistic analysis accounting for variation in bridge, ground motion, and corrosion parameters is conducted to develop time-dependent seismic fragility curves. These fragility curves indicate the evolving potential for component and system damage under seismic loading considering time-dependent corrosion-induced deterioration. The results indicate that while corrosion may actually decrease the seismic vulnerability of some components, most critical components suffer an increase in vulnerability. Quadratic models depicting the change in lognormal seismic fragility parameters are proposed to capture the time-dependent effect of aging on the fragility of the bridge system. Overall, the seismic vulnerability significantly increases throughout the lifetime of the representative bridge geometry, with a 32% shift in the median value of complete damage fragility near the end of the bridge’s life. DEWEY : 624.17 ISSN : 0733-9445 En ligne : http://ascelibrary.org/sto/resource/1/jsendh/v136/i12/p1497_s1?isAuthorized=no

Seismic reliability assessment of bridges with user - defined system failure events / Leonardo Duenas-Osorio in Journal of engineering mechanics, Vol. 137 N° 10 (Octobre 2011) 

Public ISBD [article]  in Journal of engineering mechanics > Vol. 137 N° 10 (Octobre 2011) . - pp.680-690 Titre : Seismic reliability assessment of bridges with user - defined system failure events Type de document : texte imprimé Auteurs : Leonardo Duenas-Osorio, Auteur ; Jamie E. Padgett, Auteur Année de publication : 2012 Article en page(s) : pp.680-690 Note générale : Mécanique appliquée Langues : Anglais (eng) Mots-clés : Structural  reliability  System  reliability  Bridges  Seismic  effects  Closed-form  solutions  Retrofit  Monte  Carlo  simulation Résumé : Bridge-level failure event definitions per limit state have evolved from failure of one key bridge component as representative of the whole bridge system to failure of at least one of multiple components. However, an entire set of bridge failure event possibilities exists between these two extremes in the same limit state, such as failure of any two, any three, or any desired subset of bridge components. This paper proposes a closed-form combinatorial method to evaluate all possible ways in which bridge components can fail within and across limit states. It also highlights bridge component importance measures as key by-products of the closed-form solution. Calculations are illustrated with a particular yet illustrative system failure event, called the augmented event, which incorporates failures of at least one component in a given limit state and joint failures of multiple important components in a previous limit state. Bridges in as-built and retrofitted conditions are used to illustrate the augmentation calculation under seismic loads and the application of the proposed system reliability method. The results reveal an increase in median system fragility at the moderate limit states in the range of 4–20% relative to traditional approaches that neglect augmentation. This methodology to connect bridge components to bridge system reliability can readily support infrastructure stakeholder decision making and risk management through an efficient approach that can adapt to evolving system failure event definitions. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.org/emo/resource/1/jenmdt/v137/i10/p680_s1?isAuthorized=no [article] Seismic reliability assessment of bridges with user - defined system failure events [texte imprimé] / Leonardo Duenas-Osorio, Auteur ; Jamie E. Padgett, Auteur . - 2012 . - pp.680-690. Mécanique appliquée Langues : Anglais (eng) in Journal of engineering mechanics > Vol. 137 N° 10 (Octobre 2011) . - pp.680-690 Mots-clés : Structural  reliability  System  reliability  Bridges  Seismic  effects  Closed-form  solutions  Retrofit  Monte  Carlo  simulation Résumé : Bridge-level failure event definitions per limit state have evolved from failure of one key bridge component as representative of the whole bridge system to failure of at least one of multiple components. However, an entire set of bridge failure event possibilities exists between these two extremes in the same limit state, such as failure of any two, any three, or any desired subset of bridge components. This paper proposes a closed-form combinatorial method to evaluate all possible ways in which bridge components can fail within and across limit states. It also highlights bridge component importance measures as key by-products of the closed-form solution. Calculations are illustrated with a particular yet illustrative system failure event, called the augmented event, which incorporates failures of at least one component in a given limit state and joint failures of multiple important components in a previous limit state. Bridges in as-built and retrofitted conditions are used to illustrate the augmentation calculation under seismic loads and the application of the proposed system reliability method. The results reveal an increase in median system fragility at the moderate limit states in the range of 4–20% relative to traditional approaches that neglect augmentation. This methodology to connect bridge components to bridge system reliability can readily support infrastructure stakeholder decision making and risk management through an efficient approach that can adapt to evolving system failure event definitions. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.org/emo/resource/1/jenmdt/v137/i10/p680_s1?isAuthorized=no