The Experts below are selected from a list of 273 Experts worldwide ranked by ideXlab platform
Binod Tiwari - One of the best experts on this subject based on the ideXlab platform.
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influence of relative density on static soil structure frictional resistance of dry and saturated Sand
Geotechnical and Geological Engineering, 2014Co-Authors: Binod Tiwari, Ahmed Raad AladhadhAbstract:Soil–structure frictional resistance is required while designing foundation systems and retaining walls. Although much more attention has been paid in recent years regarding soil–structure interaction for dynamic loading, highly conservative values of the static frictional resistance between soil and structure are used in design. Not much emphasis has been given lately to evaluate static frictional resistance between soil and structure. In this study, a well Graded Sand, as per USCS classification system, was prepared in the laboratory at different relative densities and moisture contents i.e. dry and saturated, and frictional resistances of those soils were measured. Those soil samples were also sheared against wood, concrete, and steel blocks and corresponding soil–structure frictional resistances were measured. Moreover, similar experiments were performed for saturated and loose poorly Graded Sand (SP), silty Sand (SM) and poorly Graded Sand with silt (SP–SM). The study result shows that the difference between frictional resistance of soil and skin friction depends on the type of soil, relative density and the moisture content. Interestingly, shear envelopes for soil–soil and soil–structure shearing resistance exhibited curvature. The traditionally adopted soil–structure frictional resistance values adopted by various geotechnical manuals were found to be highly conservative.
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Influence of Relative Density on Static Soil–Structure Frictional Resistance of Dry and Saturated Sand
Geotechnical and Geological Engineering, 2013Co-Authors: Binod Tiwari, Ahmed Raad Al-adhadhAbstract:Soil–structure frictional resistance is required while designing foundation systems and retaining walls. Although much more attention has been paid in recent years regarding soil–structure interaction for dynamic loading, highly conservative values of the static frictional resistance between soil and structure are used in design. Not much emphasis has been given lately to evaluate static frictional resistance between soil and structure. In this study, a well Graded Sand, as per USCS classification system, was prepared in the laboratory at different relative densities and moisture contents i.e. dry and saturated, and frictional resistances of those soils were measured. Those soil samples were also sheared against wood, concrete, and steel blocks and corresponding soil–structure frictional resistances were measured. Moreover, similar experiments were performed for saturated and loose poorly Graded Sand (SP), silty Sand (SM) and poorly Graded Sand with silt (SP–SM). The study result shows that the difference between frictional resistance of soil and skin friction depends on the type of soil, relative density and the moisture content. Interestingly, shear envelopes for soil–soil and soil–structure shearing resistance exhibited curvature. The traditionally adopted soil–structure frictional resistance values adopted by various geotechnical manuals were found to be highly conservative.
Ahmed Raad Al-adhadh - One of the best experts on this subject based on the ideXlab platform.
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Influence of Relative Density on Static Soil–Structure Frictional Resistance of Dry and Saturated Sand
Geotechnical and Geological Engineering, 2013Co-Authors: Binod Tiwari, Ahmed Raad Al-adhadhAbstract:Soil–structure frictional resistance is required while designing foundation systems and retaining walls. Although much more attention has been paid in recent years regarding soil–structure interaction for dynamic loading, highly conservative values of the static frictional resistance between soil and structure are used in design. Not much emphasis has been given lately to evaluate static frictional resistance between soil and structure. In this study, a well Graded Sand, as per USCS classification system, was prepared in the laboratory at different relative densities and moisture contents i.e. dry and saturated, and frictional resistances of those soils were measured. Those soil samples were also sheared against wood, concrete, and steel blocks and corresponding soil–structure frictional resistances were measured. Moreover, similar experiments were performed for saturated and loose poorly Graded Sand (SP), silty Sand (SM) and poorly Graded Sand with silt (SP–SM). The study result shows that the difference between frictional resistance of soil and skin friction depends on the type of soil, relative density and the moisture content. Interestingly, shear envelopes for soil–soil and soil–structure shearing resistance exhibited curvature. The traditionally adopted soil–structure frictional resistance values adopted by various geotechnical manuals were found to be highly conservative.
Ahmed Raad Aladhadh - One of the best experts on this subject based on the ideXlab platform.
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influence of relative density on static soil structure frictional resistance of dry and saturated Sand
Geotechnical and Geological Engineering, 2014Co-Authors: Binod Tiwari, Ahmed Raad AladhadhAbstract:Soil–structure frictional resistance is required while designing foundation systems and retaining walls. Although much more attention has been paid in recent years regarding soil–structure interaction for dynamic loading, highly conservative values of the static frictional resistance between soil and structure are used in design. Not much emphasis has been given lately to evaluate static frictional resistance between soil and structure. In this study, a well Graded Sand, as per USCS classification system, was prepared in the laboratory at different relative densities and moisture contents i.e. dry and saturated, and frictional resistances of those soils were measured. Those soil samples were also sheared against wood, concrete, and steel blocks and corresponding soil–structure frictional resistances were measured. Moreover, similar experiments were performed for saturated and loose poorly Graded Sand (SP), silty Sand (SM) and poorly Graded Sand with silt (SP–SM). The study result shows that the difference between frictional resistance of soil and skin friction depends on the type of soil, relative density and the moisture content. Interestingly, shear envelopes for soil–soil and soil–structure shearing resistance exhibited curvature. The traditionally adopted soil–structure frictional resistance values adopted by various geotechnical manuals were found to be highly conservative.
Wolfgang E. Krumbein - One of the best experts on this subject based on the ideXlab platform.
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A microscopic sedimentary succession of Graded Sand and microbial mats in modern siliciclastic tidal flats
Sedimentary Geology, 1997Co-Authors: Nora Noffke, Gisela Gerdes, Thomas Klenke, Wolfgang E. KrumbeinAbstract:Microscopic studies of thin sections from modern siliciclastic tidal flat sediments in the southern North Sea demonstrate the significant role of microbial mats in the buildup of sedimentary sequences. This is documented by a unit only a few millimetres thick. It starts at the base with a fine- to medium-grained quartz Sand often containing secondary pores (‘fenestrae type’) merging gradually into finer sediments. The lower siliciclastic part is superposed by an upper organically dominated layer built by microbial mats. Within the organic material, single quartz grains without any contact to each other are oriented with their long axes parallel to the bedding planes. Each siliciclastic part in the lower section of the unit indicates the initial deposition of coarser grains in a stronger flow regime followed by gradually decreasing flow velocities. Each microbial mat in the upper part essentially represents a period of low sedimentation rate. During its growth, grains still settle down onto the mat and become bound in the organic matrix. The orientation of these grains with their long axes parallel to the bedding plane points to an energetically suitable position to gravity achieved by the friction reduction of the soft organic matter. Repeated depositional events followed by low-rate deposition cause the buildup of various units. There is no visible reworking of the former surfaces, since the microbial mats prevent erosion during periods of increased flow. The buildup is characteristic of siliciclastic sediments repeatedly occupied, stabilized, and fixed by microbial films or mats.
Ismail Bakar - One of the best experts on this subject based on the ideXlab platform.
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EFFECT OF PARTICLE GRADING SIZE AND SHAPE ON DENSITY, DILATANCY AND SHEAR STRENGTH OF SandS
Malaysian Journal of Science, 2012Co-Authors: Alvin John, Devapriya, Adnan Zainorabidin, Ismail BakarAbstract:The science of the particle level interaction of Sandy soil on the macroscale behaviour is governed by the particle shape and size. Sands are cohesionless and the characteristics of its shear strength (Opeak and Ocr) are entirely dependent on the density, normal stress and the interparticle reaction of the soil structure. The shearing deformation of Sand has also led to a phenomenon called dilatancy (ψ). In this study, well Graded Sand (SW), poorly Graded uniform Sand (SPuKahang), gap Graded Sand (SPg) from Kahang Malaysia and also (SPuL.Buzzard) uniform Leighton Buzzard Sand from United Kingdom were tested in a direct shear box apparatus. The shapes of the Sand particles were quantified using the images obtained from a digital microscope. Results from published studies were also analyzed. It was found that the Opeak, Ocr and ψ was the highest for (SW) when compared to the others with similar relative densities (Dr). High normal stresses gave very little variations in dilation angle (ψ) between the samples tested as compared to the lower normal stress. The correlation between (Opeak - Ocr) and ψ is also a useful measure of the enhancement of strength due to dilatancy. This research also contributes to predicting potential dilatancy occurrence based on the Sand morphology. (Keywords: Sand, direct shear box test, friction angle, angle of dilatancy, size and shape)
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The Effects of Particle Morphology (Shape and Sizes) Characteristics on its Engineering Behaviour and Sustainable Engineering Performance of Sand
International Journal of Integrated Engineering, 2012Co-Authors: Meng Siang Lim, Adnan Zainorabidin, Devapriya Chitral Wijeyesekera, Ismail BakarAbstract:The mechanical behaviour of granular soil is interestingly dependent on the characteristics of the particles. The wide range of particle shapes and size distribution of Sand, by virtue of its sedimentological process of formation plays a significant factor in the influence on its engineering behaviour reflected in terms of its packing density, permeability, shear strength and dilatancy. In this study, research on well Graded Sand (SW), poorly Graded uniform Sand (SPu Kahang ), gap Graded Sand (SPg) from Kahang Malaysia and also (SPu L.Buzzard ) Leighton Buzzard Sand from UK were tested in a direct shear box. The shapes were quantified using images from a digital microscope where its morphological features can lead via statistical methods to determined correlations between strength and its physical properties. The research effort focuses in obtaining its shear strength and roughness parameters and also its extreme packing (e min and e max ). Results from published studies on related matter and also the study on permeability are presented. The findings would lead to a better way to classify the shape and size distribution for the assessment of the behaviour of Sand in various engineering disciplines such a good foundation soil in geotechnical engineering, as an abrasive material in mechanical engineering, as a filler of concrete in civil engineering, as a filter in chemical engineering and occurs as oil Sands in petroleum engineering.
