Documents disponibles écrits par cet auteur

Experimental and theoretical studies for the behavior of strip footing on oil-contaminated sand / Ahmed M. A. Nasr in Journal of geotechnical and geoenvironmental engineering, Vol. 135 N° 12 (Décembre 2009) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 135 N° 12 (Décembre 2009) . - pp. 1814–1822 Titre : Experimental and theoretical studies for the behavior of strip footing on oil-contaminated sand Type de document : texte imprimé Auteurs : Ahmed M. A. Nasr, Auteur Année de publication : 2010 Article en page(s) : pp. 1814–1822 Note générale : Geotechnical and geoenvironmental engineering Langues : Anglais (eng) Mots-clés : Oil  spillsSoil  pollutionSandSoil  typeFootingsLoad  bearing  capacityModel  testsExperimentation Résumé : This paper presents the results of a series of plain-strain model tests carried out on both clean sand and oil-contaminated sand loaded with a rigid strip footing. The objectives of this study are to determine the influence of oil-contaminated sand on the bearing capacity characteristics and the settlement of the footing. Contaminated sand layers were prepared by mixing the sand with an oil content of 0–5% with respect to dry soil to match the field conditions. The investigations are carried out by varying the depth and the length of the contaminated sand layer and the type of oil contamination. A plain-strain elastoplastic theoretical model with an interface gap element between footing and the soil is carried out to verify the test results of the model. It is shown that the load-settlement behavior and ultimate bearing capacity of the footing can be drastically reduced by oil contamination. The bearing capacity is decreased and the settlement of the footing is increased with increasing the depth and the length of the contaminated sand layer. The agreement between observed and computed results is found to be reasonably good in terms of load-settlement behavior and effect of oil contamination on the bearing capacity ratio. A comparison between the model results and the prototype scale (B=1.0 m) results are also studied. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000165 [article] Experimental and theoretical studies for the behavior of strip footing on oil-contaminated sand [texte imprimé] / Ahmed M. A. Nasr, Auteur . - 2010 . - pp. 1814–1822. Geotechnical and geoenvironmental engineering Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 135 N° 12 (Décembre 2009) . - pp. 1814–1822 Mots-clés : Oil  spillsSoil  pollutionSandSoil  typeFootingsLoad  bearing  capacityModel  testsExperimentation Résumé : This paper presents the results of a series of plain-strain model tests carried out on both clean sand and oil-contaminated sand loaded with a rigid strip footing. The objectives of this study are to determine the influence of oil-contaminated sand on the bearing capacity characteristics and the settlement of the footing. Contaminated sand layers were prepared by mixing the sand with an oil content of 0–5% with respect to dry soil to match the field conditions. The investigations are carried out by varying the depth and the length of the contaminated sand layer and the type of oil contamination. A plain-strain elastoplastic theoretical model with an interface gap element between footing and the soil is carried out to verify the test results of the model. It is shown that the load-settlement behavior and ultimate bearing capacity of the footing can be drastically reduced by oil contamination. The bearing capacity is decreased and the settlement of the footing is increased with increasing the depth and the length of the contaminated sand layer. The agreement between observed and computed results is found to be reasonably good in terms of load-settlement behavior and effect of oil contamination on the bearing capacity ratio. A comparison between the model results and the prototype scale (B=1.0 m) results are also studied. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000165

Uplift behavior of vertical piles embedded in oil-contaminated sand / Ahmed M. A. Nasr in Journal of geotechnical and geoenvironmental engineering, Vol. 139 N° 1 (Janvier 2013) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 139 N° 1 (Janvier 2013) . - pp. 162-174 Titre : Uplift behavior of vertical piles embedded in oil-contaminated sand Type de document : texte imprimé Auteurs : Ahmed M. A. Nasr, Auteur Année de publication : 2013 Article en page(s) : pp. 162-174 Note générale : geotechnique Langues : Anglais (eng) Mots-clés : uplifting;  piles;  sand  (soil  type);  soil  pollution;  model  tests;  experimentation Résumé : There are several problems when dealing with oil-contaminated soil that affect environmental quality and alter the geotechnical properties of the soil. The influence of oil contamination on the uplift performance of model concrete piles embedded in sand at various densities is investigated. In this study, the model parameters are varied, namely, the thickness and diameter of the contaminated layer, type of oil contamination, pile surface roughness, and pile installation method. Contaminated-sand layers were prepared by mixing the sand with an oil content of 0–3% with respect to dry soil to match the field conditions. The results were then analyzed to study the effect of each parameter. To evaluate the scale effects, two sizes of model piles were tested, and the results were compared. This paper also discussed the effect of oil contamination on the relative ground movement around the pile surface. The results indicated that the uplift resistance was drastically reduced by oil contamination. The maximum reduction in uplift resistance and skin friction factor occurred at low contamination (oil content = 1%). The initial sand density and method of pile installation are significant factors affecting uplift capacity of piles embedded in oil-contaminated sand. The experimental results were used for the development of linear regression equations. These equations relate the uplift capacity ratio for piles embedded in contaminated sand to the aforementioned parameters. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000739 [article] Uplift behavior of vertical piles embedded in oil-contaminated sand [texte imprimé] / Ahmed M. A. Nasr, Auteur . - 2013 . - pp. 162-174. geotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 139 N° 1 (Janvier 2013) . - pp. 162-174 Mots-clés : uplifting;  piles;  sand  (soil  type);  soil  pollution;  model  tests;  experimentation Résumé : There are several problems when dealing with oil-contaminated soil that affect environmental quality and alter the geotechnical properties of the soil. The influence of oil contamination on the uplift performance of model concrete piles embedded in sand at various densities is investigated. In this study, the model parameters are varied, namely, the thickness and diameter of the contaminated layer, type of oil contamination, pile surface roughness, and pile installation method. Contaminated-sand layers were prepared by mixing the sand with an oil content of 0–3% with respect to dry soil to match the field conditions. The results were then analyzed to study the effect of each parameter. To evaluate the scale effects, two sizes of model piles were tested, and the results were compared. This paper also discussed the effect of oil contamination on the relative ground movement around the pile surface. The results indicated that the uplift resistance was drastically reduced by oil contamination. The maximum reduction in uplift resistance and skin friction factor occurred at low contamination (oil content = 1%). The initial sand density and method of pile installation are significant factors affecting uplift capacity of piles embedded in oil-contaminated sand. The experimental results were used for the development of linear regression equations. These equations relate the uplift capacity ratio for piles embedded in contaminated sand to the aforementioned parameters. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000739