Documents disponibles écrits par cet auteur

Experimental and computational evaluation of in-span hinges in reinforced concrete box-girder bridges / Matias A. Hube in Journal of structural engineering, Vol. 137 N° 11 (Novembre 2011) 

Public ISBD [article]  in Journal of structural engineering > Vol. 137 N° 11 (Novembre 2011) . - pp. 1245-1253 Titre : Experimental and computational evaluation of in-span hinges in reinforced concrete box-girder bridges Type de document : texte imprimé Auteurs : Matias A. Hube, Auteur ; Khalid M. Mosalam, Auteur Année de publication : 2012 Article en page(s) : pp. 1245-1253 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Box  girders  Bridges  Experimentation  Finite-element  method  In-span  hinges  Reinforced  concrete Résumé : During the last three decades, considerable research efforts have sought to improve the seismic design of California highway bridges. However, the in-span hinge (ISH) regions of concrete box girders have not been studied adequately. ISHs are classified as disturbed regions because of the concentrated bearing loads and the possible existence of utility and maintenance openings, which induce a three-dimensional (3D) behavior. Nevertheless, ISHs are commonly designed as two-dimensional short cantilevers, following standard procedures in “Building Code Requirements for Structural Concrete and Commentary” of the American Concrete Institute. These designs typically lead to congested reinforcement, causing constructability concerns from practical and economical aspects. In this study, the strength of current ISHs is assessed by using a combined experimental and computational approach. For the experimental part, two 1/3-scale specimens were tested at the University of California, Berkeley. The computational part adopted nonlinear 3D finite elements considering embedded reinforcement and concrete cracking. Failure modes were identified, and realistic idealizations of the behavior of the ISHs were developed. The findings from this study revealed that ISHs fail with a combination of two failure modes: (1) beam shear and (2) punching shear. DEWEY : 624.17 ISSN : 0733-9445 En ligne : http://ascelibrary.org/sto/resource/1/jsendh/v137/i11/p1245_s1?isAuthorized=no [article] Experimental and computational evaluation of in-span hinges in reinforced concrete box-girder bridges [texte imprimé] / Matias A. Hube, Auteur ; Khalid M. Mosalam, Auteur . - 2012 . - pp. 1245-1253. Génie Civil Langues : Anglais (eng) in Journal of structural engineering > Vol. 137 N° 11 (Novembre 2011) . - pp. 1245-1253 Mots-clés : Box  girders  Bridges  Experimentation  Finite-element  method  In-span  hinges  Reinforced  concrete Résumé : During the last three decades, considerable research efforts have sought to improve the seismic design of California highway bridges. However, the in-span hinge (ISH) regions of concrete box girders have not been studied adequately. ISHs are classified as disturbed regions because of the concentrated bearing loads and the possible existence of utility and maintenance openings, which induce a three-dimensional (3D) behavior. Nevertheless, ISHs are commonly designed as two-dimensional short cantilevers, following standard procedures in “Building Code Requirements for Structural Concrete and Commentary” of the American Concrete Institute. These designs typically lead to congested reinforcement, causing constructability concerns from practical and economical aspects. In this study, the strength of current ISHs is assessed by using a combined experimental and computational approach. For the experimental part, two 1/3-scale specimens were tested at the University of California, Berkeley. The computational part adopted nonlinear 3D finite elements considering embedded reinforcement and concrete cracking. Failure modes were identified, and realistic idealizations of the behavior of the ISHs were developed. The findings from this study revealed that ISHs fail with a combination of two failure modes: (1) beam shear and (2) punching shear. DEWEY : 624.17 ISSN : 0733-9445 En ligne : http://ascelibrary.org/sto/resource/1/jsendh/v137/i11/p1245_s1?isAuthorized=no

Experimental investigation of nonductile RC corner beam-column joints with floor slabs / Sangjoon Park in Journal of structural engineering, Vol. 139 N° 1 (Janvier 2013) 

Public ISBD [article]  in Journal of structural engineering > Vol. 139 N° 1 (Janvier 2013) . - pp. 1–14 Titre : Experimental investigation of nonductile RC corner beam-column joints with floor slabs Type de document : texte imprimé Auteurs : Sangjoon Park, Auteur ; Khalid M. Mosalam, Auteur Année de publication : 2013 Article en page(s) : pp. 1–14 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : ASCE  41  Beam-column  joints  Cyclic  loading  Experiments  Reinforced  concrete  Seismic  design  Shear  strength  Slabs Résumé : The paper presents the experimental investigation of full-scale RC corner beam-column joints without transverse reinforcement in the joint region leading to nonductile behavior in many exiting RC buildings. The experimental study considered two design parameters: joint aspect ratio and beam longitudinal reinforcement ratio. Four corner beam-column joint specimens were constructed with transverse beams and floor slabs and tested under quasi-static cyclic loading. The specimens experienced joint shear failure without beam hinging mechanism as a result of the absence of transverse reinforcement in the joint region. On the basis of the test results, the paper discusses the effects of these two design parameters and the floor slab on the behavior of corner beam-column joints. The joint shear strengths obtained from the test specimens are compared with the strength recommendations of the ASCE/SEI 41-06 provisions. ISSN : 0733-9445 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29ST.1943-541X.0000591 [article] Experimental investigation of nonductile RC corner beam-column joints with floor slabs [texte imprimé] / Sangjoon Park, Auteur ; Khalid M. Mosalam, Auteur . - 2013 . - pp. 1–14. Génie Civil Langues : Anglais (eng) in Journal of structural engineering > Vol. 139 N° 1 (Janvier 2013) . - pp. 1–14 Mots-clés : ASCE  41  Beam-column  joints  Cyclic  loading  Experiments  Reinforced  concrete  Seismic  design  Shear  strength  Slabs Résumé : The paper presents the experimental investigation of full-scale RC corner beam-column joints without transverse reinforcement in the joint region leading to nonductile behavior in many exiting RC buildings. The experimental study considered two design parameters: joint aspect ratio and beam longitudinal reinforcement ratio. Four corner beam-column joint specimens were constructed with transverse beams and floor slabs and tested under quasi-static cyclic loading. The specimens experienced joint shear failure without beam hinging mechanism as a result of the absence of transverse reinforcement in the joint region. On the basis of the test results, the paper discusses the effects of these two design parameters and the floor slab on the behavior of corner beam-column joints. The joint shear strengths obtained from the test specimens are compared with the strength recommendations of the ASCE/SEI 41-06 provisions. ISSN : 0733-9445 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29ST.1943-541X.0000591

Modeling progressive collapse in reinforced concrete buildings using direct element removal / Mohamed Talaat in Earthquake engineering structural dynamics, Vol. 38 N°5 (Avril 2009) 

Public ISBD [article]  in Earthquake engineering structural dynamics > Vol. 38 N°5 (Avril 2009) . - pp. 609-634 Titre : Modeling progressive collapse in reinforced concrete buildings using direct element removal Type de document : texte imprimé Auteurs : Mohamed Talaat, Auteur ; Khalid M. Mosalam, Auteur Article en page(s) : pp. 609-634 Note générale : Génie Civile Langues : Anglais (eng) Mots-clés : Dynamic  analysis;  Element  removal;  Finite  element;  Progressive  collapse;  Reinforced  concrete  frame;  Unreinforced  masonry  infill Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : This paper presents a novel analytical formulation of an element removal algorithm based on dynamic equilibrium and the resulting transient change in system kinematics, by applying imposed accelerations instead of external forces at a node where an element was once connected. The algorithm is implemented into an open-source finite element code, numerically tested using a benchmark structural system with simplified element removal criteria, and able to capture the effect of uncertainty in member capacity. Realistic element removal criteria are introduced for mode-dependent gravity load collapse of seismically deficient and retrofitted reinforced concrete (RC) columns and unreinforced masonry (URM) infill walls. Two applications are conducted using structural systems of RC frames with URM infill walls. The first is a probabilistic study of a one-story model subjected to an ensemble of 14 ground motion recordings from similar neighboring sites during an earthquake event. The study produces empirical probability curves for partial and complete collapse conditioned on different hazard levels, and concludes that the intra-event variability is a major source of uncertainty affecting the outcome of progressive collapse simulations. The second application is a deterministic sensitivity study of progressive collapse response in a five-story structural model to uncertainty in live load, stiffness, damping, and seismic hazard level, subjected to one ground motion record. The analysis identifies the time at incipient collapse as an adequate sensitivity measure, and the uncertainty in ground motion intensity as the most important, followed by the stiffness of the URM infill wall. ISSN : 0098-8847 En ligne : http://www3.interscience.wiley.com/journal/122198914/abstract [article] Modeling progressive collapse in reinforced concrete buildings using direct element removal [texte imprimé] / Mohamed Talaat, Auteur ; Khalid M. Mosalam, Auteur . - pp. 609-634. Génie Civile Langues : Anglais (eng) in Earthquake engineering structural dynamics > Vol. 38 N°5 (Avril 2009) . - pp. 609-634 Mots-clés : Dynamic  analysis;  Element  removal;  Finite  element;  Progressive  collapse;  Reinforced  concrete  frame;  Unreinforced  masonry  infill Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : This paper presents a novel analytical formulation of an element removal algorithm based on dynamic equilibrium and the resulting transient change in system kinematics, by applying imposed accelerations instead of external forces at a node where an element was once connected. The algorithm is implemented into an open-source finite element code, numerically tested using a benchmark structural system with simplified element removal criteria, and able to capture the effect of uncertainty in member capacity. Realistic element removal criteria are introduced for mode-dependent gravity load collapse of seismically deficient and retrofitted reinforced concrete (RC) columns and unreinforced masonry (URM) infill walls. Two applications are conducted using structural systems of RC frames with URM infill walls. The first is a probabilistic study of a one-story model subjected to an ensemble of 14 ground motion recordings from similar neighboring sites during an earthquake event. The study produces empirical probability curves for partial and complete collapse conditioned on different hazard levels, and concludes that the intra-event variability is a major source of uncertainty affecting the outcome of progressive collapse simulations. The second application is a deterministic sensitivity study of progressive collapse response in a five-story structural model to uncertainty in live load, stiffness, damping, and seismic hazard level, subjected to one ground motion record. The analysis identifies the time at incipient collapse as an adequate sensitivity measure, and the uncertainty in ground motion intensity as the most important, followed by the stiffness of the URM infill wall. ISSN : 0098-8847 En ligne : http://www3.interscience.wiley.com/journal/122198914/abstract

Seismic evaluation of 1940s asymmetric wood-frame building using conventional measurements and high-definition laser scanning / Khalid M. Mosalam in Earthquake engineering structural dynamics, Vol. 38 N° 10 (Août 2009) 

Public ISBD [article]  in Earthquake engineering structural dynamics > Vol. 38 N° 10 (Août 2009) . - pp. 1175-1197 Titre : Seismic evaluation of 1940s asymmetric wood-frame building using conventional measurements and high-definition laser scanning Type de document : texte imprimé Auteurs : Khalid M. Mosalam, Auteur ; Shakhzod M. Takhirov, Auteur ; Alidad Hashemi, Auteur Article en page(s) : pp. 1175-1197 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : House-over-garage;  Laser  scan;  Shake  table.  Soft  story;  Torsion  ;Wood-frame Résumé : This study presents results from shake table experiments of a wood-frame building conducted at the University of California, Berkeley. A 13.5-ft × 19.5-ft two-story wood-frame building representing San Francisco 1940s design of a residential building with a garage space on the first story (house-over-garage) was tested. The test building was subjected to scaled ground motion based on Los Gatos record from Loma Prieta 1989 earthquake. The strong motion time history was scaled to match design spectra of a site in Richmond district of San Francisco. The test results demonstrated the seismic vulnerability of the test building due to soft story mechanism and significant twisting when shaken in two horizontal directions. In addition to conventional instrumentation for measuring acceleration and position of selected points of the test building, high-definition laser scanning technology was employed to assess global and local anomalies of the building after the shake table tests. The analysis conducted in this study showed very good correlation between conventional data recorded from position transducers and the laser scans. These laser scans expanded limits of conventional data at discrete points and allowed analyzing the whole building after shaking. DEWEY : 624.1 ISSN : 0098-8847 En ligne : www.interscience.wiley.com/journal/eqe [article] Seismic evaluation of 1940s asymmetric wood-frame building using conventional measurements and high-definition laser scanning [texte imprimé] / Khalid M. Mosalam, Auteur ; Shakhzod M. Takhirov, Auteur ; Alidad Hashemi, Auteur . - pp. 1175-1197. Génie Civil Langues : Anglais (eng) in Earthquake engineering structural dynamics > Vol. 38 N° 10 (Août 2009) . - pp. 1175-1197 Mots-clés : House-over-garage;  Laser  scan;  Shake  table.  Soft  story;  Torsion  ;Wood-frame Résumé : This study presents results from shake table experiments of a wood-frame building conducted at the University of California, Berkeley. A 13.5-ft × 19.5-ft two-story wood-frame building representing San Francisco 1940s design of a residential building with a garage space on the first story (house-over-garage) was tested. The test building was subjected to scaled ground motion based on Los Gatos record from Loma Prieta 1989 earthquake. The strong motion time history was scaled to match design spectra of a site in Richmond district of San Francisco. The test results demonstrated the seismic vulnerability of the test building due to soft story mechanism and significant twisting when shaken in two horizontal directions. In addition to conventional instrumentation for measuring acceleration and position of selected points of the test building, high-definition laser scanning technology was employed to assess global and local anomalies of the building after the shake table tests. The analysis conducted in this study showed very good correlation between conventional data recorded from position transducers and the laser scans. These laser scans expanded limits of conventional data at discrete points and allowed analyzing the whole building after shaking. DEWEY : 624.1 ISSN : 0098-8847 En ligne : www.interscience.wiley.com/journal/eqe

Shake-table experiment on reinforced concrete structure containing masonry infill wall / Hashem, Alidad in Earthquake engineering structural dynamics, Vol. 35 N° 14 (Novembre 2006) 

Public ISBD [article]  in Earthquake engineering structural dynamics > Vol. 35 N° 14 (Novembre 2006) . - 1827 - 1852 p. Titre : Shake-table experiment on reinforced concrete structure containing masonry infill wall Type de document : texte imprimé Auteurs : Hashem, Alidad, Auteur ; Khalid M. Mosalam, Auteur Article en page(s) : 1827 - 1852 p. Note générale : Génie civil Langues : Anglais (eng) Mots-clés : Earthquakes  Infilled  frame  •  modelling  Reinforced  concrete  Shake-table  URM  wall  Tremblements  de  terre  Armature  de  remplissage  Modélisation  Béton  armé  Table  de  secousse  Mur  d'URM Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : A hypothetical 5-storey prototype structure with reinforced concrete (RC) frame and unreinforced masonry (URM) wall is considered. The paper focuses on a shake-table experiment conducted on a substructure of this prototype consisting of the middle bays of its first storey. A test structure is constructed to represent the selected substructure and the relationship between demand parameters of the test structure and those of the prototype structure is established using computational modelling. The dynamic properties of the test structure are determined using a number of preliminary tests before performing the shake-table experiments. Based on these tests and results obtained from computational modelling of the test structure, the test ground motions and the sequence of shakings are determined. The results of the shake-table tests in terms of the global and local responses and the effects of the URM infill wall on the structural behaviour and the dynamic properties of the RC test structure are presented. Finally, the test results are compared to analytical ones obtained from further computational modelling of the test structure subjected to the measured shake-table accelerations. Une structure hypothétique du prototype 5-niveaux avec l'armature (RC) concrète renforcée et le mur non renforcé de la maçonnerie (URM) est considérée. Le papier se concentre sur une expérience de secouer-table entreprise sur une sous-structure de ce prototype comprenant les compartiments moyens de son premier étage. Une structure d'essai est construite pour représenter la sous-structure choisie et le rapport entre les paramètres de la demande de la structure d'essai et ceux de la structure de prototype est établi en utilisant modélisation informatique. Les propriétés dynamiques de la structure d'essai sont déterminées en utilisant un certain nombre d'essais de préliminaire avant d'exécuter les expériences de table de secousse. Basé sur ces essais et résultats obtenus à partir de modélisation informatique de la structure d'essai, les mouvements au sol d'essai et l'ordre des shakings sont déterminés. Les résultats des essais de secouer-table en termes de réponses globales et locales et effets du mur de remplissage d'URM sur le comportement structural et propriétés dynamiques de la structure d'essai de RC sont présentés. En conclusion, les résultats d'essai sont comparés aux analyses obtenues à partir davantage de modélisation informatique de la structure d'essai soumise aux accélérations mesurées de table de secousse. DEWEY : 551.2 ISSN : 0098-8847 RAMEAU : Armature -- Béton armé -- Tremblement de terre En ligne : http://www3.interscience.wiley.com/cgi-bin/abstract/11273 [article] Shake-table experiment on reinforced concrete structure containing masonry infill wall [texte imprimé] / Hashem, Alidad, Auteur ; Khalid M. Mosalam, Auteur . - 1827 - 1852 p. Génie civil Langues : Anglais (eng) in Earthquake engineering structural dynamics > Vol. 35 N° 14 (Novembre 2006) . - 1827 - 1852 p. Mots-clés : Earthquakes  Infilled  frame  •  modelling  Reinforced  concrete  Shake-table  URM  wall  Tremblements  de  terre  Armature  de  remplissage  Modélisation  Béton  armé  Table  de  secousse  Mur  d'URM Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : A hypothetical 5-storey prototype structure with reinforced concrete (RC) frame and unreinforced masonry (URM) wall is considered. The paper focuses on a shake-table experiment conducted on a substructure of this prototype consisting of the middle bays of its first storey. A test structure is constructed to represent the selected substructure and the relationship between demand parameters of the test structure and those of the prototype structure is established using computational modelling. The dynamic properties of the test structure are determined using a number of preliminary tests before performing the shake-table experiments. Based on these tests and results obtained from computational modelling of the test structure, the test ground motions and the sequence of shakings are determined. The results of the shake-table tests in terms of the global and local responses and the effects of the URM infill wall on the structural behaviour and the dynamic properties of the RC test structure are presented. Finally, the test results are compared to analytical ones obtained from further computational modelling of the test structure subjected to the measured shake-table accelerations. Une structure hypothétique du prototype 5-niveaux avec l'armature (RC) concrète renforcée et le mur non renforcé de la maçonnerie (URM) est considérée. Le papier se concentre sur une expérience de secouer-table entreprise sur une sous-structure de ce prototype comprenant les compartiments moyens de son premier étage. Une structure d'essai est construite pour représenter la sous-structure choisie et le rapport entre les paramètres de la demande de la structure d'essai et ceux de la structure de prototype est établi en utilisant modélisation informatique. Les propriétés dynamiques de la structure d'essai sont déterminées en utilisant un certain nombre d'essais de préliminaire avant d'exécuter les expériences de table de secousse. Basé sur ces essais et résultats obtenus à partir de modélisation informatique de la structure d'essai, les mouvements au sol d'essai et l'ordre des shakings sont déterminés. Les résultats des essais de secouer-table en termes de réponses globales et locales et effets du mur de remplissage d'URM sur le comportement structural et propriétés dynamiques de la structure d'essai de RC sont présentés. En conclusion, les résultats d'essai sont comparés aux analyses obtenues à partir davantage de modélisation informatique de la structure d'essai soumise aux accélérations mesurées de table de secousse. DEWEY : 551.2 ISSN : 0098-8847 RAMEAU : Armature -- Béton armé -- Tremblement de terre En ligne : http://www3.interscience.wiley.com/cgi-bin/abstract/11273

Simulation of the shaking table test of a seven-story shear wall building / Mohamed Talaat in Earthquake engineering structural dynamics, Vol. 38 N°5 (Avril 2009) 

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Towards error-free hybrid simulation using mixed variables / Tarek Elkhoraibi in Earthquake engineering structural dynamics, Vol. 36 N°11 (Octobre 2007) 

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