Documents disponibles écrits par cet auteur

Central artery/tunnel project excavation induced ground deformations / Youssef M.A. Hashash in Journal of geotechnical and geoenvironmental engineering, Vol. 134 n°9 (Septembre 2008) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 134 n°9 (Septembre 2008) . - pp. 1399–1406 Titre : Central artery/tunnel project excavation induced ground deformations Type de document : texte imprimé Auteurs : Youssef M.A. Hashash, Auteur ; Abdolreza Osouli, Auteur ; Camilo Marulanda, Auteur Année de publication : 2008 Article en page(s) : pp. 1399–1406 Note générale : Geotechnical and geoenvironmental engineering Langues : Anglais (eng) Mots-clés : Excavation  Soil  deformation  Tunnels  Urban  areas Résumé : Estimate of deformations around urban excavations is a primary concern for designers, contractors, owners, and potentially affected third parties. Significant efforts have gone into the development of empirically based methods to estimate deformations relying on a large number of case histories. The construction of the deep excavations for the central artery/tunnel project provides valuable information on observed deformations due to the construction of these excavations. Lateral deformations and surface settlements for three construction contracts are collected and summarized in a form similar to published empirical charts. The stiff support system used in these braced excavation and the embedment of the wall into stiff strata control deformations to minimal levels. The data show that surface settlements, although small, extend farther away from the excavation than previously reported. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%291090-0241%282008%29134%3A9%2813 [...] [article] Central artery/tunnel project excavation induced ground deformations [texte imprimé] / Youssef M.A. Hashash, Auteur ; Abdolreza Osouli, Auteur ; Camilo Marulanda, Auteur . - 2008 . - pp. 1399–1406. Geotechnical and geoenvironmental engineering Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 134 n°9 (Septembre 2008) . - pp. 1399–1406 Mots-clés : Excavation  Soil  deformation  Tunnels  Urban  areas Résumé : Estimate of deformations around urban excavations is a primary concern for designers, contractors, owners, and potentially affected third parties. Significant efforts have gone into the development of empirically based methods to estimate deformations relying on a large number of case histories. The construction of the deep excavations for the central artery/tunnel project provides valuable information on observed deformations due to the construction of these excavations. Lateral deformations and surface settlements for three construction contracts are collected and summarized in a form similar to published empirical charts. The stiff support system used in these braced excavation and the embedment of the wall into stiff strata control deformations to minimal levels. The data show that surface settlements, although small, extend farther away from the excavation than previously reported. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%291090-0241%282008%29134%3A9%2813 [...]

Influence of softening on mine floor-bearing capacity / Gennaro G. Marino in Journal of geotechnical and geoenvironmental engineering, Vol. 138 N° 10 (Octobre 2012) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 138 N° 10 (Octobre 2012) . - pp.1284–1297. Titre : Influence of softening on mine floor-bearing capacity : Case history Type de document : texte imprimé Auteurs : Gennaro G. Marino, Auteur ; Abdolreza Osouli, Auteur Année de publication : 2013 Article en page(s) : pp.1284–1297. Note générale : Géotechnique Langues : Anglais (eng) Mots-clés : Rock  softening  Mine  floor  properties  Bearing  strength  Floor  stability  analysis Résumé : This paper introduces a new approach that considers the effect of softening to more accurately calculate floor-bearing capacities where difficult mine conditions are present. Because of softening and changes in confining pressures, the geotechnical properties of immediate fine-grained rock vary in the mine floor. Therefore, when floor softening is present, the conventional equations used to determine the floor-bearing capacity are not very accurate. In this study, a methodology is presented that considers the floor softening and existence of a durable layer in the mine floor. The proposed method is based on analysis of a case study located in central Illinois utilizing finite-element method (FEM) and rock mechanics laboratory data. For this case study, extensive geological mapping and laboratory tests, including rock classification, rock swell properties, and triaxial compression tests, were conducted on samples of fine-grained rocks that predominantly consisted of mudstone. The results of laboratory tests are presented and discussed in detail. Aerial and cross-sectional analyses of the floor lithology and stratigraphy were performed to evaluate the important bearing conditions across the project site. From the analyses, the immediate floor thickness and type of the nondurable and the underlying durable rock across the site were determined. DuroIndex is presented and used to determine and rate the durability of mine floor material. Considering certain pillar-to-room width ratios, two-dimensional FEM analyses were performed to evaluate mine floor capacity with both softened and unsoftened floor conditions. Consequently, the softening correction factor, or the correction for the softening effect, was determined. Finally, a procedure that takes into account the effect of softening and the existence of a durable layer was developed to determine allowable floor-bearing capacity. ISSN : 1090-0241 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000693 [article] Influence of softening on mine floor-bearing capacity : Case history [texte imprimé] / Gennaro G. Marino, Auteur ; Abdolreza Osouli, Auteur . - 2013 . - pp.1284–1297. Géotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 138 N° 10 (Octobre 2012) . - pp.1284–1297. Mots-clés : Rock  softening  Mine  floor  properties  Bearing  strength  Floor  stability  analysis Résumé : This paper introduces a new approach that considers the effect of softening to more accurately calculate floor-bearing capacities where difficult mine conditions are present. Because of softening and changes in confining pressures, the geotechnical properties of immediate fine-grained rock vary in the mine floor. Therefore, when floor softening is present, the conventional equations used to determine the floor-bearing capacity are not very accurate. In this study, a methodology is presented that considers the floor softening and existence of a durable layer in the mine floor. The proposed method is based on analysis of a case study located in central Illinois utilizing finite-element method (FEM) and rock mechanics laboratory data. For this case study, extensive geological mapping and laboratory tests, including rock classification, rock swell properties, and triaxial compression tests, were conducted on samples of fine-grained rocks that predominantly consisted of mudstone. The results of laboratory tests are presented and discussed in detail. Aerial and cross-sectional analyses of the floor lithology and stratigraphy were performed to evaluate the important bearing conditions across the project site. From the analyses, the immediate floor thickness and type of the nondurable and the underlying durable rock across the site were determined. DuroIndex is presented and used to determine and rate the durability of mine floor material. Considering certain pillar-to-room width ratios, two-dimensional FEM analyses were performed to evaluate mine floor capacity with both softened and unsoftened floor conditions. Consequently, the softening correction factor, or the correction for the softening effect, was determined. Finally, a procedure that takes into account the effect of softening and the existence of a durable layer was developed to determine allowable floor-bearing capacity. ISSN : 1090-0241 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000693

Interplay between field measurements and soil behavior for capturing supported excavation response / Abdolreza Osouli in Journal of geotechnical and geoenvironmental engineering, Vol. 136 N° 1 (Janvier 2010) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 136 N° 1 (Janvier 2010) . - pp. 69-84 Titre : Interplay between field measurements and soil behavior for capturing supported excavation response Type de document : texte imprimé Auteurs : Abdolreza Osouli, Auteur ; Youssef M.A. Hashash, Auteur ; Hwayeon Song, Auteur Article en page(s) : pp. 69-84 Note générale : Géotechnique Langues : Anglais (eng) Mots-clés : Excavations  Soil  behavior  Inverse  analysis  Instrumentation Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : Instruments are installed during the construction of urban excavations to monitor ground response at discrete locations to various construction activities, to verify design assumptions and to effectively apply the observational approach. Inverse analysis approaches are often used to develop improved soil models suitable for representing soil response during excavation from these measurements. We propose that through the integration of inverse analysis and instrument measurements, it is possible to provide information on excavation performance at locations where no instrumentation is available. Therefore, this study examines the relationship between various instruments typically used on an excavation project and the quality of information that can be extracted for excavation modeling. A synthetically generated set of instrument measurements that include inclinometers, surface settlement points, extensometers, heave gauges, piezometers, and strain gauges, using an idealized soil profile are initially used. The analyses show that in addition to the measurements of lateral wall deflections and surface settlement, inclinometers placed some distance behind the wall and measured forces in the struts significantly improve the quality of the extracted soil behavior. These findings are further demonstrated with a well instrumented deep excavation case study in Taipei. The inclinometers at the wall and at farther distance from the wall are used to extract the soil behavior. The extracted soil model used in a numerical analysis provides a good prediction of excavation behavior elsewhere around the excavation including surface settlements. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.aip.org/vsearch/servlet/VerityServlet?KEY=JGGEFK&smode=strres [...] [article] Interplay between field measurements and soil behavior for capturing supported excavation response [texte imprimé] / Abdolreza Osouli, Auteur ; Youssef M.A. Hashash, Auteur ; Hwayeon Song, Auteur . - pp. 69-84. Géotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 136 N° 1 (Janvier 2010) . - pp. 69-84 Mots-clés : Excavations  Soil  behavior  Inverse  analysis  Instrumentation Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : Instruments are installed during the construction of urban excavations to monitor ground response at discrete locations to various construction activities, to verify design assumptions and to effectively apply the observational approach. Inverse analysis approaches are often used to develop improved soil models suitable for representing soil response during excavation from these measurements. We propose that through the integration of inverse analysis and instrument measurements, it is possible to provide information on excavation performance at locations where no instrumentation is available. Therefore, this study examines the relationship between various instruments typically used on an excavation project and the quality of information that can be extracted for excavation modeling. A synthetically generated set of instrument measurements that include inclinometers, surface settlement points, extensometers, heave gauges, piezometers, and strain gauges, using an idealized soil profile are initially used. The analyses show that in addition to the measurements of lateral wall deflections and surface settlement, inclinometers placed some distance behind the wall and measured forces in the struts significantly improve the quality of the extracted soil behavior. These findings are further demonstrated with a well instrumented deep excavation case study in Taipei. The inclinometers at the wall and at farther distance from the wall are used to extract the soil behavior. The extracted soil model used in a numerical analysis provides a good prediction of excavation behavior elsewhere around the excavation including surface settlements. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.aip.org/vsearch/servlet/VerityServlet?KEY=JGGEFK&smode=strres [...]