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Anil Kumar Mishra - One of the best experts on this subject based on the ideXlab platform.
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undrained performance of sustainable Compacted Sand bentonite glass fiber composite for landfill application
Journal of Cleaner Production, 2020Co-Authors: Krishanu Mukherjee, Anil Kumar MishraAbstract:Abstract A Compacted Sand-bentonite composite is considered as a barrier material for the use at the landfill. If the strength of the barrier material is not adequate, then the actual operation of the liner system can be endangered. Worldwide environmental awareness and high dumping cost have influenced the possible use of glass fibers for landfill application. Since the composite possessed a lower shear strength, glass fiber can be added to enhance its shear strength. The purpose of the present investigation was to assess the effective shear strength parameters of Compacted Sand–bentonite mixture, mixed in a proportion of 80:20 and reinforced with glass fiber. Glass fiber with an aspect ratio of 40, 80, and 120 were added to Sand-bentonite composite in a fraction of 0.5, 1, and 1.5%. Test result suggested that the negative excess pore water pressure increased for the composite with an aspect ratio of 40; however, it decreased gradually with an increase in the aspect ratio to 80 and 120 for any fiber concentration. At a fiber content of 1.5% with the aspect ratio of 80 and 120, the peak effective frictional angle was almost constant. The cohesion component enhanced moderately up to the aspect ratio of 80 for any fiber concentration and remained constant with a further increase in the aspect ratio from 80 to 120. Residual strength parameter of the composite improved significantly with the addition of glass fiber. Initial tangent increased up to 1% fiber content for any aspect ratio, and then reduced with the further addition of glass fiber. The effective principal stress at failure predicted using a mathematical model showed an excellent agreement between predicted and experimental values.
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performance enhancement of Sand bentonite mixture due to addition of fiber and geosynthetic clay liner
International Journal of Geotechnical Engineering, 2016Co-Authors: Krishanu Mukherjee, Anil Kumar MishraAbstract:In the absence of impermeable natural soils, Compacted Sand–bentonite mixture along with a layer of geosynthetic clay liner (GCL) is used as a liner material at the waste disposal site. However, due to desiccation, the bentonite present in the liner shrinks resulting in an increase in the hydraulic conductivity of the liner. To prevent the desiccation cracking of bentonite, glass fibre is added to the mixture as a reinforcing material. However, the addition of the fibre can influence the geotechnical properties of liner material. To study the effect of the fibre on the geotechnical properties of the Sand–bentonite mixtures with one layer of GCL, glass fibre of 10 mm length was added in the proportion of 0.5 and 1.0% to different Sand–bentonite mixtures. Result shows that the swelling pressure and swelling potential of the soil–bentonite mixture with a layer of GCL decreased significantly with the increase in the glass fibre content in the mixture. The hydraulic conductivity of the mixtures was decreased w...
Krishanu Mukherjee - One of the best experts on this subject based on the ideXlab platform.
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undrained performance of sustainable Compacted Sand bentonite glass fiber composite for landfill application
Journal of Cleaner Production, 2020Co-Authors: Krishanu Mukherjee, Anil Kumar MishraAbstract:Abstract A Compacted Sand-bentonite composite is considered as a barrier material for the use at the landfill. If the strength of the barrier material is not adequate, then the actual operation of the liner system can be endangered. Worldwide environmental awareness and high dumping cost have influenced the possible use of glass fibers for landfill application. Since the composite possessed a lower shear strength, glass fiber can be added to enhance its shear strength. The purpose of the present investigation was to assess the effective shear strength parameters of Compacted Sand–bentonite mixture, mixed in a proportion of 80:20 and reinforced with glass fiber. Glass fiber with an aspect ratio of 40, 80, and 120 were added to Sand-bentonite composite in a fraction of 0.5, 1, and 1.5%. Test result suggested that the negative excess pore water pressure increased for the composite with an aspect ratio of 40; however, it decreased gradually with an increase in the aspect ratio to 80 and 120 for any fiber concentration. At a fiber content of 1.5% with the aspect ratio of 80 and 120, the peak effective frictional angle was almost constant. The cohesion component enhanced moderately up to the aspect ratio of 80 for any fiber concentration and remained constant with a further increase in the aspect ratio from 80 to 120. Residual strength parameter of the composite improved significantly with the addition of glass fiber. Initial tangent increased up to 1% fiber content for any aspect ratio, and then reduced with the further addition of glass fiber. The effective principal stress at failure predicted using a mathematical model showed an excellent agreement between predicted and experimental values.
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performance enhancement of Sand bentonite mixture due to addition of fiber and geosynthetic clay liner
International Journal of Geotechnical Engineering, 2016Co-Authors: Krishanu Mukherjee, Anil Kumar MishraAbstract:In the absence of impermeable natural soils, Compacted Sand–bentonite mixture along with a layer of geosynthetic clay liner (GCL) is used as a liner material at the waste disposal site. However, due to desiccation, the bentonite present in the liner shrinks resulting in an increase in the hydraulic conductivity of the liner. To prevent the desiccation cracking of bentonite, glass fibre is added to the mixture as a reinforcing material. However, the addition of the fibre can influence the geotechnical properties of liner material. To study the effect of the fibre on the geotechnical properties of the Sand–bentonite mixtures with one layer of GCL, glass fibre of 10 mm length was added in the proportion of 0.5 and 1.0% to different Sand–bentonite mixtures. Result shows that the swelling pressure and swelling potential of the soil–bentonite mixture with a layer of GCL decreased significantly with the increase in the glass fibre content in the mixture. The hydraulic conductivity of the mixtures was decreased w...
Fannir Jamal - One of the best experts on this subject based on the ideXlab platform.
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Stabilité des écoulements diphasiques dans un milieu poreux étudié par des techniques d'IRM
HAL CCSD, 2019Co-Authors: Fannir JamalAbstract:It is important to understand the driving forces that control the flow of two immiscible fluids in a porous medium. Indeed, there is a wide range of applications of two-phase flows in porous media, especially those relating to enhanced oil recovery (EOR). The development of quantitative magnetic resonance imaging (MRI) techniques opens up new possibilities for studying and characterizing multiphase flows in porous media. This work is specifically concerned with describing the displacement of two immiscible fluids (water-oil) in a porous medium using MRI techniques. The porous medium is initially saturated with oil which is displaced by injecting water from below, oil and water can be evacuated from above. The general objective of the study is to determine the displacement and the deformation of the front (water-oil) over time, and to specify the trapping mechanisms of the phases. Experiments are conducted on two porous models. One oil wetting consists of a stack of small polystyrene beads (0.4 mm < dp < 0.6 mm), the other wetting with water is a slightly Compacted Sand (0.02 mm < dp
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Stabilité des écoulements diphasiques dans un milieu poreux étudié par des techniques d'IRM
2019Co-Authors: Fannir JamalAbstract:Il est important de comprendre les forces motrices qui contrôlent l'écoulement de deux fluides immiscibles dans un milieu poreux. En effet, il existe une large gamme d'applications des écoulements diphasiques en milieux poreux, notamment ceux qui concernent la récupération assistée du pétrole (EOR). Le développement des techniques quantitatives d'imagerie par résonance magnétique (IRM) ouvre de nouvelles possibilités pour étudier et caractériser les flux multiphasiques en milieu poreux. Ce travail s’intéresse précisément à décrire le déplacement de deux fluides immiscibles (eau-huile) au sein d’un milieu poreux en utilisant les techniques d’IRM. Le milieu poreux est initialement saturé d’huile qu’on vient déplacer en injectant de l’eau par le bas, l’huile et l’eau pouvant s’évacuer par le haut. L’objectif général de l’étude est de déterminer le déplacement et la déformation du front (eau-huile) au cours du temps, et de préciser les mécanismes de piégeage des phases. Des expériences sont menées sur deux modèles poreux. L’un mouillant à l’huile consiste en un empilement de petites billes en polystyrène (0,4 mm < dp < 0,6 mm), l’autre mouillant à l’eau est un sable légèrement compacté (0,02 mm < dp < 0,50 mm). Nous avons utilisé un dispositif de micro-imagerie RMN fonctionnant à 14 T (résonance 1H à 600 MHz) pour acquérir des images à haute résolution (0.2 mm) à l’intérieur des milieux poreux au cours du déplacement des deux fluides. Les résultats obtenus ont montré que le profil de saturation en huile est fortement influencé par les propriétés du matériau poreux, telles que la porosité et la perméabilité de l'échantillon, le mouillage des phases, le débit d'injection de l’eau ou encore l’hétérogénéité de la matrice solide. L'influence du débit d’injection d’eau sur la saturation résiduelle en huile a été plus particulièrement étudiée. Les résultats expérimentaux permettent une compréhension fine du déplacement de deux fluides non miscibles pour deux types de milieux poreux, qui se différencient principalement par les effets de la mouillabilité. Dans le même temps, une simulation numérique du déplacement vertical ascendant de l’huile poussée par de l’eau dans une colonne poreuse a été réalisée et les résultats ont été comparés à nos expériences sous IRM.It is important to understand the driving forces that control the flow of two immiscible fluids in a porous medium. Indeed, there is a wide range of applications of two-phase flows in porous media, especially those relating to enhanced oil recovery (EOR). The development of quantitative magnetic resonance imaging (MRI) techniques opens up new possibilities for studying and characterizing multiphase flows in porous media. This work is specifically concerned with describing the displacement of two immiscible fluids (water-oil) in a porous medium using MRI techniques. The porous medium is initially saturated with oil which is displaced by injecting water from below, oil and water can be evacuated from above. The general objective of the study is to determine the displacement and the deformation of the front (water-oil) over time, and to specify the trapping mechanisms of the phases. Experiments are conducted on two porous models. One oil wetting consists of a stack of small polystyrene beads (0.4 mm < dp < 0.6 mm), the other wetting with water is a slightly Compacted Sand (0.02 mm < dp
Lennon Ferreira Tomasi - One of the best experts on this subject based on the ideXlab platform.
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the impact of dry unit weight and cement content on the durability of Sand cement blends
Proceedings of the Institution of Civil Engineers - Ground Improvement, 2017Co-Authors: Nilo Cesar Consoli, Lennon Ferreira TomasiAbstract:Increasing the dry unit weight (γd) through vibration/compaction and the addition of Portland cement are among promising ground improvement procedures to enhance the endurance performance of granular materials. The present investigation intends to compute the impact of cement content (C) and γd on the durability of Osorio Sand–Portland cement blends. An experimental programme of wetting–drying cycle tests considering distinct γd and C was carried out to assess that influence. A steadiness of the characteristic loss of mass (CLM) during 12 wetting–drying cycles for distinct specimens (of each particular γd and C) is observed and suggests a possibility of carrying out just a few cycles, making possible to extrapolate the results up to the required 12 cycles, reducing the time needed to assess the durability of such blends. It is also shown that the CLM of each specimen is reduced on increasing the γd and C. The CLM and accumulated loss of mass of Compacted Sand–cement mixes during wetting–drying cycles were...
Hisham T Eid - One of the best experts on this subject based on the ideXlab platform.
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shear strength of geosynthetic composite systems for design of landfill liner and cover slopes
Geotextiles and Geomembranes, 2011Co-Authors: Hisham T EidAbstract:Abstract Torsional ring shear tests were performed on composite specimens that simulate the field alignment of municipal solid waste (MSW) landfill liner and cover system components. Simultaneous shearing was provided to each test specimen without forcing failure to occur through a pre-determined plane. Composite liner specimens consisted of a textured geomembrane (GM) underlain by a needle-punched geosynthetic clay liner (GCL) which in turn underlain by a Compacted silty clay. Hydrated specimens were sheared at eleven different normal stress levels. Test results revealed that shear strength of the composite liner system can be controlled by different failure modes depending on the magnitude of normal stress and the comparative values of the GCL interface and internal shear strength. Failure following these modes may result in a bilinear or trilinear peak strength envelope and a corresponding stepped residual strength envelope. Composite cover specimens that comprised textured GM placed on unreinforced smooth GM-backed GCL resting on Compacted Sand were sheared at five different GCL hydration conditions and a normal stress that is usually imposed on MSW landfill cover geosynthetic components. Test results showed that increasing the GCL hydration moves the shearing plane from the GCL smooth GM backing/Sand interface to that of the textured GM/hydrated bentonite. Effects of these interactive shear strength behaviors of composite liner and cover system components on the possibility of developing progressive failure in landfill slopes were discussed. Recommendations for designing landfill geosynthetic-lined slopes were subsequently given. Three-dimensional stability analysis of well-documented case history of failed composite system slope was presented to support the introduced results and recommendations.