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Analytical modeling and design validation of posttensioned precast concrete coupling beams for seismic regions / Brad D. Weldon in Journal of structural engineering, Vol. 138 N° 2 (Fevrier 2012) 

Public ISBD [article]  in Journal of structural engineering > Vol. 138 N° 2 (Fevrier 2012) . - pp. 224-234 Titre : Analytical modeling and design validation of posttensioned precast concrete coupling beams for seismic regions Type de document : texte imprimé Auteurs : Brad D. Weldon, Auteur ; Yahya C. Kurama, Auteur Année de publication : 2012 Article en page(s) : pp. 224-234 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Posttensioned  concrete  Precast  concrete  Prestressed  concrete  Reinforced  concrete  Coupled  walls  Coupling  Seismic  analysis  Seismic  design  Shear  walls Résumé : This paper provides an experimental validation on the analytical modeling and design of unbonded posttensioned precast concrete coupling beams. Previous test results from a series of floor-level coupling beam subassembly specimens are compared with the predicted results from a fiber-element analytical model. The test results are also used to validate an idealized coupling beam end moment versus chord rotation relationship that was developed as a design tool following basic principles of equilibrium, compatibility, and constitutive relationships. Based on the experimental and analytical comparisons, the paper presents a seismic design approach to achieve the desired lateral strength, stiffness, ductility, and energy dissipation capacity in unbonded posttensioned precast coupling beams. DEWEY : 624.17 ISSN : 0733-9445 En ligne : http://ascelibrary.org/sto/resource/1/jsendh/v138/i2/p224_s1?isAuthorized=no [article] Analytical modeling and design validation of posttensioned precast concrete coupling beams for seismic regions [texte imprimé] / Brad D. Weldon, Auteur ; Yahya C. Kurama, Auteur . - 2012 . - pp. 224-234. Génie Civil Langues : Anglais (eng) in Journal of structural engineering > Vol. 138 N° 2 (Fevrier 2012) . - pp. 224-234 Mots-clés : Posttensioned  concrete  Precast  concrete  Prestressed  concrete  Reinforced  concrete  Coupled  walls  Coupling  Seismic  analysis  Seismic  design  Shear  walls Résumé : This paper provides an experimental validation on the analytical modeling and design of unbonded posttensioned precast concrete coupling beams. Previous test results from a series of floor-level coupling beam subassembly specimens are compared with the predicted results from a fiber-element analytical model. The test results are also used to validate an idealized coupling beam end moment versus chord rotation relationship that was developed as a design tool following basic principles of equilibrium, compatibility, and constitutive relationships. Based on the experimental and analytical comparisons, the paper presents a seismic design approach to achieve the desired lateral strength, stiffness, ductility, and energy dissipation capacity in unbonded posttensioned precast coupling beams. DEWEY : 624.17 ISSN : 0733-9445 En ligne : http://ascelibrary.org/sto/resource/1/jsendh/v138/i2/p224_s1?isAuthorized=no

Design and measured behavior of a hybrid precast concrete wall specimen for seismic regions / Brian J. Smith in Journal of structural engineering, Vol. 137 N° 10 (Octobre 2011) 

Public ISBD [article]  in Journal of structural engineering > Vol. 137 N° 10 (Octobre 2011) . - pp. 1052-1062 Titre : Design and measured behavior of a hybrid precast concrete wall specimen for seismic regions Type de document : texte imprimé Auteurs : Brian J. Smith, Auteur ; Yahya C. Kurama, Auteur ; Michael J. McGinnis, Auteur Année de publication : 2012 Article en page(s) : pp. 1052-1062 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Posttensioned  concrete  Precast  concrete  Reinforced  concrete  Digital  image  correlation  Seismic  tests  Hybrid  walls  Shear  walls Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : This paper presents the measured behavior from the testing of a 0.4-scale “hybrid” precast concrete wall specimen under reversed-cyclic lateral loading and provides an assessment of the seismic design and analysis of the wall by using the experimental results. The hybrid precast wall system investigated in the paper utilizes a combination of mild (i.e., Grade 400) steel and high-strength unbonded posttensioning (PT) steel for lateral resistance across horizontal joints. A seismic design procedure that conforms to ACI 318 and ACI ITG-5.2 was used for the design of the test specimen based on ACI ITG-5.1. The behavior of the specimen was measured with conventional data acquisition techniques and also full-field digital image correlation of the base panel and the critical joint between the base panel and the foundation, providing unprecedented information on the wall performance. The paper compares these measurements with the design and analytical predictions, focusing specifically on the applied lateral load and displacement, energy dissipation, behavior of the steel reinforcement, and behavior along the horizontal joints. The test specimen was not able to reach the expected ultimate drift level owing to a combination of poor unconfined concrete strength and poor placement of the confinement reinforcement at the toes. However, the performance of the wall up to the failure point was consistent with the predicted behavior based on both the design procedure and the analytical models. DEWEY : 624.17 ISSN : 0733-9445 En ligne : http://ascelibrary.org/sto/resource/1/jsendh/v137/i10/p1052_s1?isAuthorized=no [article] Design and measured behavior of a hybrid precast concrete wall specimen for seismic regions [texte imprimé] / Brian J. Smith, Auteur ; Yahya C. Kurama, Auteur ; Michael J. McGinnis, Auteur . - 2012 . - pp. 1052-1062. Génie Civil Langues : Anglais (eng) in Journal of structural engineering > Vol. 137 N° 10 (Octobre 2011) . - pp. 1052-1062 Mots-clés : Posttensioned  concrete  Precast  concrete  Reinforced  concrete  Digital  image  correlation  Seismic  tests  Hybrid  walls  Shear  walls Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : This paper presents the measured behavior from the testing of a 0.4-scale “hybrid” precast concrete wall specimen under reversed-cyclic lateral loading and provides an assessment of the seismic design and analysis of the wall by using the experimental results. The hybrid precast wall system investigated in the paper utilizes a combination of mild (i.e., Grade 400) steel and high-strength unbonded posttensioning (PT) steel for lateral resistance across horizontal joints. A seismic design procedure that conforms to ACI 318 and ACI ITG-5.2 was used for the design of the test specimen based on ACI ITG-5.1. The behavior of the specimen was measured with conventional data acquisition techniques and also full-field digital image correlation of the base panel and the critical joint between the base panel and the foundation, providing unprecedented information on the wall performance. The paper compares these measurements with the design and analytical predictions, focusing specifically on the applied lateral load and displacement, energy dissipation, behavior of the steel reinforcement, and behavior along the horizontal joints. The test specimen was not able to reach the expected ultimate drift level owing to a combination of poor unconfined concrete strength and poor placement of the confinement reinforcement at the toes. However, the performance of the wall up to the failure point was consistent with the predicted behavior based on both the design procedure and the analytical models. DEWEY : 624.17 ISSN : 0733-9445 En ligne : http://ascelibrary.org/sto/resource/1/jsendh/v137/i10/p1052_s1?isAuthorized=no

Experimental evaluation of posttensioned precast concrete coupling beams / Brad D. Weldon in Journal of structural engineering, Vol. 136 N° 9 (Septembre 2010) 

Public ISBD [article]  in Journal of structural engineering > Vol. 136 N° 9 (Septembre 2010) . - pp. 1066-1077 Titre : Experimental evaluation of posttensioned precast concrete coupling beams Type de document : texte imprimé Auteurs : Brad D. Weldon, Auteur ; Yahya C. Kurama, Auteur Année de publication : 2011 Article en page(s) : pp. 1066-1077 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Concrete  Posttensioned  Concrete  Precast  Concrete  Prestressed  Concrete  Reinforced  Coupled  walls  Coupling  Tests  Seismic  Walls  Shear Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : This paper describes the results from eight half-scale experiments of unbonded posttensioned precast concrete coupling beams under reversed-cyclic lateral loading. Each test specimen includes a coupling beam and the adjacent concrete wall pier regions at a floor level. Under lateral loads, the nonlinear displacements of unbonded posttensioned coupling beams are governed by the opening of gaps at the beam-to-wall joints. Steel top and seat angles are used at the beam ends to yield and provide energy dissipation. The test parameters include the beam posttensioning tendon area and initial stress, initial beam concrete axial stress, angle strength, and beam depth. The results demonstrate the lateral stiffness, strength, and ductility of the coupling beams under cyclic loading, with considerable energy dissipation concentrated in the angles. It is shown that the residual displacements of the structure upon unloading are small due to the restoring effect of the posttensioning force. The sustained chord rotation capacities of the test specimens are compared with those from previous tests of monolithic coupling beams. DEWEY : 624.17 ISSN : 0733-9445 En ligne : http://ascelibrary.org/sto/resource/1/jsendh/v136/i9/p1066_s1?isAuthorized=no [article] Experimental evaluation of posttensioned precast concrete coupling beams [texte imprimé] / Brad D. Weldon, Auteur ; Yahya C. Kurama, Auteur . - 2011 . - pp. 1066-1077. Génie Civil Langues : Anglais (eng) in Journal of structural engineering > Vol. 136 N° 9 (Septembre 2010) . - pp. 1066-1077 Mots-clés : Concrete  Posttensioned  Concrete  Precast  Concrete  Prestressed  Concrete  Reinforced  Coupled  walls  Coupling  Tests  Seismic  Walls  Shear Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : This paper describes the results from eight half-scale experiments of unbonded posttensioned precast concrete coupling beams under reversed-cyclic lateral loading. Each test specimen includes a coupling beam and the adjacent concrete wall pier regions at a floor level. Under lateral loads, the nonlinear displacements of unbonded posttensioned coupling beams are governed by the opening of gaps at the beam-to-wall joints. Steel top and seat angles are used at the beam ends to yield and provide energy dissipation. The test parameters include the beam posttensioning tendon area and initial stress, initial beam concrete axial stress, angle strength, and beam depth. The results demonstrate the lateral stiffness, strength, and ductility of the coupling beams under cyclic loading, with considerable energy dissipation concentrated in the angles. It is shown that the residual displacements of the structure upon unloading are small due to the restoring effect of the posttensioning force. The sustained chord rotation capacities of the test specimens are compared with those from previous tests of monolithic coupling beams. DEWEY : 624.17 ISSN : 0733-9445 En ligne : http://ascelibrary.org/sto/resource/1/jsendh/v136/i9/p1066_s1?isAuthorized=no