Documents disponibles écrits par cet auteur

Aluminum waste reaction indicators in a municipal solid waste landfill / Timothy D. Stark in Journal of geotechnical and geoenvironmental engineering, Vol. 138 N° 3 (Mars 2012) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 138 N° 3 (Mars 2012) . - pp. 252-261 Titre : Aluminum waste reaction indicators in a municipal solid waste landfill Type de document : texte imprimé Auteurs : Timothy D. Stark, Auteur ; Jeffrey W. Martin, Auteur ; Gina T. Gerbasi, Auteur Année de publication : 2012 Article en page(s) : pp. 252-261 Note générale : Géotechnique Langues : Anglais (eng) Mots-clés : Solid  waste  Leachate  Stability  Leachate  recirculation  Aluminum  Exothermic  chemical  reaction  Waste  disposal  MSW  Subsurface  fire Résumé : Subtitle D landfills may contain aluminum from residential and commercial solid waste, industrial waste, and aluminum production wastes. Some aluminum-bearing waste materials, particularly aluminum production wastes, may react with liquid in a landfill and cause uncontrolled temperature increases, significant changes in gas composition and pressure, nuisance odors, and changes in leachate composition and quantity. Such reactions may also cause degradation of leachate quality (e.g., increased ammonia, sodium, potassium, chloride, and TDS concentrations), combustion of the surrounding waste, damage to engineered components (gas collection systems, leachate collection systems, and liner system materials), and slope instability. Temperatures exceeding 150°C (300°F), generation and accumulation of undesirable explosive and toxic gases (e.g., hydrogen, acetylene, ammonia, carbon monoxide, and benzene), and gas pressures exceeding 210 kPa (30.5 psi) have been observed. Water from leachate recirculation, precipitation, the waste, or groundwater infiltration can initiate the exothermic reaction if aluminum production wastes are present. This paper uses a case history to illustrate some indicators of an aluminum reaction and problems that can develop from such a reaction in a Subtitle D landfill. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/gto/resource/1/jggefk/v138/i3/p252_s1?isAuthorized=no [article] Aluminum waste reaction indicators in a municipal solid waste landfill [texte imprimé] / Timothy D. Stark, Auteur ; Jeffrey W. Martin, Auteur ; Gina T. Gerbasi, Auteur . - 2012 . - pp. 252-261. Géotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 138 N° 3 (Mars 2012) . - pp. 252-261 Mots-clés : Solid  waste  Leachate  Stability  Leachate  recirculation  Aluminum  Exothermic  chemical  reaction  Waste  disposal  MSW  Subsurface  fire Résumé : Subtitle D landfills may contain aluminum from residential and commercial solid waste, industrial waste, and aluminum production wastes. Some aluminum-bearing waste materials, particularly aluminum production wastes, may react with liquid in a landfill and cause uncontrolled temperature increases, significant changes in gas composition and pressure, nuisance odors, and changes in leachate composition and quantity. Such reactions may also cause degradation of leachate quality (e.g., increased ammonia, sodium, potassium, chloride, and TDS concentrations), combustion of the surrounding waste, damage to engineered components (gas collection systems, leachate collection systems, and liner system materials), and slope instability. Temperatures exceeding 150°C (300°F), generation and accumulation of undesirable explosive and toxic gases (e.g., hydrogen, acetylene, ammonia, carbon monoxide, and benzene), and gas pressures exceeding 210 kPa (30.5 psi) have been observed. Water from leachate recirculation, precipitation, the waste, or groundwater infiltration can initiate the exothermic reaction if aluminum production wastes are present. This paper uses a case history to illustrate some indicators of an aluminum reaction and problems that can develop from such a reaction in a Subtitle D landfill. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/gto/resource/1/jggefk/v138/i3/p252_s1?isAuthorized=no

Compacted soil liner interface strength importance / Timothy D. Stark in Journal of geotechnical and geoenvironmental engineering, Vol. 138 N° 4 (Avril 2012) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 138 N° 4 (Avril 2012) . - pp. 544–550 Titre : Compacted soil liner interface strength importance Type de document : texte imprimé Auteurs : Timothy D. Stark, Auteur ; Hangseok Choi, Auteur ; Chulho Lee, Auteur Année de publication : 2012 Article en page(s) : pp. 544–550 Note générale : Géologie appliquée Langues : Anglais (eng) Mots-clés : Slope  stability  Landfills  Geomembranes  Geosynthetics  Compacted  soil  liner  Geosynthetic  lined  slopes  Interface  shear  strength Résumé : This paper describes an interesting slope failure in a liner system of a municipal solid waste containment facility during construction because the sliding interface is not the geomembrane (GM)/compacted low-permeability soil liner (LPSL) but a soil–soil interface within the LPSL. Some of the lessons learned are as follows: (1) compaction of the LPSL should ensure that each lift is kneaded into the lower lift so a weak interface is not created in the LPSL; (2) the LPSL moisture content should be controlled so it does not exceed the specified value, for example 3–4% wet of optimum, because it can lead to a weak interface in the LPSL; (3) drainage material should be placed over the GM from the slope toe to the top to reduce the shear stresses applied to the weakest interface; and (4) equipment should not move laterally across the slope if it is unsupported but up the slope while placing the cover soil from bottom to top. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000556 [article] Compacted soil liner interface strength importance [texte imprimé] / Timothy D. Stark, Auteur ; Hangseok Choi, Auteur ; Chulho Lee, Auteur . - 2012 . - pp. 544–550. Géologie appliquée Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 138 N° 4 (Avril 2012) . - pp. 544–550 Mots-clés : Slope  stability  Landfills  Geomembranes  Geosynthetics  Compacted  soil  liner  Geosynthetic  lined  slopes  Interface  shear  strength Résumé : This paper describes an interesting slope failure in a liner system of a municipal solid waste containment facility during construction because the sliding interface is not the geomembrane (GM)/compacted low-permeability soil liner (LPSL) but a soil–soil interface within the LPSL. Some of the lessons learned are as follows: (1) compaction of the LPSL should ensure that each lift is kneaded into the lower lift so a weak interface is not created in the LPSL; (2) the LPSL moisture content should be controlled so it does not exceed the specified value, for example 3–4% wet of optimum, because it can lead to a weak interface in the LPSL; (3) drainage material should be placed over the GM from the slope toe to the top to reduce the shear stresses applied to the weakest interface; and (4) equipment should not move laterally across the slope if it is unsupported but up the slope while placing the cover soil from bottom to top. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000556

Fill placement on slopes underlain by franciscan mélange / Timothy D. Stark in Journal of geotechnical and geoenvironmental engineering, Vol. 137 N° 3 (Mars 2011) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 137 N° 3 (Mars 2011) . - pp. 263-272 Titre : Fill placement on slopes underlain by franciscan mélange Type de document : texte imprimé Auteurs : Timothy D. Stark, Auteur ; Erik J. Newman, Auteur ; Gregory de la Pea, Auteur Année de publication : 2011 Article en page(s) : pp. 263-272 Note générale : Géotechnique Langues : Anglais (eng) Mots-clés : Landslides  Shear  strength  Slope  stability  Subsurface  investigation  Serpentinite  Franciscan  complex  Mélange  Block-in-matrix  rock Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : Distress in two housing developments was caused by a deep bedrock landslide triggered by placement of a large upslope fill. The large fill was placed to create a visual barrier between the upslope development and downslope housing developments and to balance the cut and fill quantities for the upslope site. This case history presents some of the ramifications of fill placement on natural slopes surrounded by urban areas, such as overstressing underlying weak material that may exist below the depth of borings typically conducted for single family residences and office complexes; the importance of surface and subsurface information in a formation known locally as Franciscan complex/mélange (which is a block-in-matrix rock formation common to the area); the shear behavior of serpentinite, which is part of the Franciscan complex; and the importance of natural and man-made changes to a slope, such as rainfall, surficial grading, home construction, and fill placement. It also illustrates the importance of locating the critical slope cross section before construction and the proper use of back-analyses in a landslide investigation. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/gto/resource/1/jggefk/v137/i3/p263_s1?isAuthorized=no [article] Fill placement on slopes underlain by franciscan mélange [texte imprimé] / Timothy D. Stark, Auteur ; Erik J. Newman, Auteur ; Gregory de la Pea, Auteur . - 2011 . - pp. 263-272. Géotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 137 N° 3 (Mars 2011) . - pp. 263-272 Mots-clés : Landslides  Shear  strength  Slope  stability  Subsurface  investigation  Serpentinite  Franciscan  complex  Mélange  Block-in-matrix  rock Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : Distress in two housing developments was caused by a deep bedrock landslide triggered by placement of a large upslope fill. The large fill was placed to create a visual barrier between the upslope development and downslope housing developments and to balance the cut and fill quantities for the upslope site. This case history presents some of the ramifications of fill placement on natural slopes surrounded by urban areas, such as overstressing underlying weak material that may exist below the depth of borings typically conducted for single family residences and office complexes; the importance of surface and subsurface information in a formation known locally as Franciscan complex/mélange (which is a block-in-matrix rock formation common to the area); the shear behavior of serpentinite, which is part of the Franciscan complex; and the importance of natural and man-made changes to a slope, such as rainfall, surficial grading, home construction, and fill placement. It also illustrates the importance of locating the critical slope cross section before construction and the proper use of back-analyses in a landslide investigation. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/gto/resource/1/jggefk/v137/i3/p263_s1?isAuthorized=no

Shear strength in preexisting landslides / Timothy D. Stark in Journal of geotechnical and geoenvironmental engineering, Vol. 136 N° 7 (Juillet 2010) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 136 N° 7 (Juillet 2010) . - pp. 957-962 Titre : Shear strength in preexisting landslides Type de document : texte imprimé Auteurs : Timothy D. Stark, Auteur ; Manzoor Hussain, Auteur Année de publication : 2010 Article en page(s) : pp. 957-962 Note générale : Géotechnique Langues : Anglais (eng) Mots-clés : Soil  mechanics  Landslides  Overconsolidated  clays  Shear  strength  Strength  recovery  Slope  stability  Ring  shear  test Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : Drained residual shear strength is used for the analysis of slopes containing preexisting shear surfaces. Some recent research suggests that preexisting shear surfaces in prior landslides can gain strength with time. Torsional ring and direct shear tests performed during this study show that the recovered shear strength measured in the laboratory is only noticeably greater than the drained residual strength at effective normal stress of 100 kPa or less. The test results also show that the recovered strength even at effective normal stresses of 100 kPa or less is lost after a small shear displacement, i.e., slope movement. An effective normal stress of 100 kPa corresponds to a shallow depth so the observed strength gain has little, if any, impact on the analysis of deep landslides. This paper describes the laboratory strength recovery testing and the results for soils with different plasticities at various rest periods and effective normal stresses. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/gto/resource/1/jggefk/v136/i7/p957_s1?isAuthorized=no [article] Shear strength in preexisting landslides [texte imprimé] / Timothy D. Stark, Auteur ; Manzoor Hussain, Auteur . - 2010 . - pp. 957-962. Géotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 136 N° 7 (Juillet 2010) . - pp. 957-962 Mots-clés : Soil  mechanics  Landslides  Overconsolidated  clays  Shear  strength  Strength  recovery  Slope  stability  Ring  shear  test Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : Drained residual shear strength is used for the analysis of slopes containing preexisting shear surfaces. Some recent research suggests that preexisting shear surfaces in prior landslides can gain strength with time. Torsional ring and direct shear tests performed during this study show that the recovered shear strength measured in the laboratory is only noticeably greater than the drained residual strength at effective normal stress of 100 kPa or less. The test results also show that the recovered strength even at effective normal stresses of 100 kPa or less is lost after a small shear displacement, i.e., slope movement. An effective normal stress of 100 kPa corresponds to a shallow depth so the observed strength gain has little, if any, impact on the analysis of deep landslides. This paper describes the laboratory strength recovery testing and the results for soils with different plasticities at various rest periods and effective normal stresses. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/gto/resource/1/jggefk/v136/i7/p957_s1?isAuthorized=no