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Earthquake safety evaluation of gravity dams considering aftershocks and reduced drainage efficiency / Pierre-Marie Alliard in Journal of engineering mechanics, Vol. 134 N°1 (Janvier 2008) 

Public ISBD [article]  in Journal of engineering mechanics > Vol. 134 N°1 (Janvier 2008) . - pp.12–22. Titre : Earthquake safety evaluation of gravity dams considering aftershocks and reduced drainage efficiency Type de document : texte imprimé Auteurs : Pierre-Marie Alliard, Auteur ; Pierre Léger, Auteur Année de publication : 2008 Article en page(s) : pp.12–22. Note générale : Mécanique appliquée Langues : Anglais (eng) Mots-clés : Dam  safety  Uplift  pressure  Sliding  Displacement  Seismic  effects  Dilatancy  Hydromechanics Résumé : This paper develops a methodology to perform seismic response analyses of concrete gravity dams considering aftershocks, and reduced drainage efficiency due to disruption of the drainage system. A database of earthquake records has been assembled to characterize main shocks and aftershocks. A drain finite difference hydraulic model considering laminar or turbulent two-dimensional flow in connecting cracks, geometrical distortions due to joint dilatancy while sliding, and misaligned drain segments is developed and validated. Coupled-hydromechanical analyses on the seismic response of a drained 90m gravity dam are used to show the importance of cumulative displacements on the increase in uplift pressures, drain flow, and reduced sliding safety factors. Aftershock response is especially sensitive to the drainage system dimensions and model parameters, such as the foundation stiffness, and the number of potentially sliding joints. The proposed methodology forms the basis to develop displacement based performance criteria in stability evaluation of existing dams reevaluated for much higher ground motions intensities that they have been designed for many years ago. ISSN : 0733-9399 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%290733-9399%282008%29134%3A1%2812 [...] [article] Earthquake safety evaluation of gravity dams considering aftershocks and reduced drainage efficiency [texte imprimé] / Pierre-Marie Alliard, Auteur ; Pierre Léger, Auteur . - 2008 . - pp.12–22. Mécanique appliquée Langues : Anglais (eng) in Journal of engineering mechanics > Vol. 134 N°1 (Janvier 2008) . - pp.12–22. Mots-clés : Dam  safety  Uplift  pressure  Sliding  Displacement  Seismic  effects  Dilatancy  Hydromechanics Résumé : This paper develops a methodology to perform seismic response analyses of concrete gravity dams considering aftershocks, and reduced drainage efficiency due to disruption of the drainage system. A database of earthquake records has been assembled to characterize main shocks and aftershocks. A drain finite difference hydraulic model considering laminar or turbulent two-dimensional flow in connecting cracks, geometrical distortions due to joint dilatancy while sliding, and misaligned drain segments is developed and validated. Coupled-hydromechanical analyses on the seismic response of a drained 90m gravity dam are used to show the importance of cumulative displacements on the increase in uplift pressures, drain flow, and reduced sliding safety factors. Aftershock response is especially sensitive to the drainage system dimensions and model parameters, such as the foundation stiffness, and the number of potentially sliding joints. The proposed methodology forms the basis to develop displacement based performance criteria in stability evaluation of existing dams reevaluated for much higher ground motions intensities that they have been designed for many years ago. ISSN : 0733-9399 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%290733-9399%282008%29134%3A1%2812 [...]