The Experts below are selected from a list of 84 Experts worldwide ranked by ideXlab platform
Zhen Fang - One of the best experts on this subject based on the ideXlab platform.
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responses of excess pore water pressure in Soft marine clay around a Soil cement column
International Journal of Geomechanics, 2007Co-Authors: Zhen FangAbstract:The Soil ground treated by deep cement mixing (DCM) in the field normally consists of cement–Soil mixed columns and untreated Soils. Although many attempts have been made, research on the consolidation behavior of the treated Soil ground has been limited. To better understand the consolidation process of the DCM treated ground, in this study, an axisymmetric physical model test with full instrumentation was carried out. The physical model ground consisted of a central cement–Soil column and Surrounding Soft Soil. Excess pore water pressures in the Soil and vertical pressures carried by the DCM column and the untreated Soil were recorded throughout the test. Responses of excess pore pressure under loading and unloading stages are highlighted. Based on the data analysis, it is revealed that the improved ground consolidates faster than the pure Soil ground. The major reason is considered to be that the DCM column reduces the vertical stress increment in the Soil and results in a lower value of excess pore pr...
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Responses of Excess Pore Water Pressure in Soft Marine Clay around a Soil–Cement Column
International Journal of Geomechanics, 2007Co-Authors: Zhen Fang, Jianhua YinAbstract:The Soil ground treated by deep cement mixing (DCM) in the field normally consists of cement–Soil mixed columns and untreated Soils. Although many attempts have been made, research on the consolidation behavior of the treated Soil ground has been limited. To better understand the consolidation process of the DCM treated ground, in this study, an axisymmetric physical model test with full instrumentation was carried out. The physical model ground consisted of a central cement–Soil column and Surrounding Soft Soil. Excess pore water pressures in the Soil and vertical pressures carried by the DCM column and the untreated Soil were recorded throughout the test. Responses of excess pore pressure under loading and unloading stages are highlighted. Based on the data analysis, it is revealed that the improved ground consolidates faster than the pure Soil ground. The major reason is considered to be that the DCM column reduces the vertical stress increment in the Soil and results in a lower value of excess pore pr...
Ashim Kanti Dey - One of the best experts on this subject based on the ideXlab platform.
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Bearing capacity of geogrid reinforced sand over encased stone columns in Soft clay
Geotextiles and Geomembranes, 2017Co-Authors: Prasenjit Debnath, Ashim Kanti DeyAbstract:Abstract Stone columns develop their load carrying capacity from the circumferential confinement provided by the Surrounding Soils. In very Soft Soils, the circumferential confinement offered by the Surrounding Soft Soil may not be sufficient to develop the required load carrying capacity. Hence a vertical confinement would yield a better result. The load carrying capacity is further increased with the addition of a sand bed over the stone columns. In the present study, a series of laboratory model tests on an unreinforced sand bed (USB) and a geogrid-reinforced sand bed (GRSB) placed over a group of vertically encased stone columns (VESC) floating in Soft clay and their numerical simulations were conducted. Three-dimensional numerical simulations were performed using a finite element package ABAQUS 6.12. In the finite element analysis, geogrid and geotextile were modeled as an elasto-plastic material. As compared to unreinforced clay bed, an 8.45 fold increase in bearing capacity was observed with the provision of a GRSB over VESC. The optimum thickness of USB and GRSB was found to be 0.2 times and 0.15 times the diameter of the footing. A considerable decrease in bulging of columns was also noticed with the provision of a GRSB over VESC. Both the improvement factor and stress concentration ratio of VESC with GRSB showed an increasing trend with an increase in the settlement. It was observed that the optimum length of stone columns and the optimum depth of encasement of the group of floating VESC with GRSB are 6 times and about 3 times the diameter of the column respectively.
Antonio Silva Cardoso - One of the best experts on this subject based on the ideXlab platform.
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embankments on Soft Soil reinforced with stone columns numerical analysis and proposal of a new design method
Geotechnical and Geological Engineering, 2009Co-Authors: Jose Leitao Borges, Tiago Sabino Domingues, Antonio Silva CardosoAbstract:A parametric study of an embankment on Soft Soils reinforced with stone columns is performed using a computer program based on the finite element method. The cylindrical unit cell formulation is used by modeling one column and its Surrounding Soft Soil with confined axisymmetric behaviour. The computer program incorporates the Biot consolidation theory (coupled formulation of the flow and equilibrium equations) with constitutive relations simulated by the p–q–θ critical state model. The following parameters are analysed: the replacement area ratio, the deformability of the column material, the thickness of the Soft Soil, the deformability of the fill and the friction angle of the column material. Based on the results of this study, a new design method is proposed, relating the settlement improvement factor to the two factors that revealed major influence: the replacement area ratio and the ratio between the deformability of the Soft Soil and the deformability of the column material.
Prasenjit Debnath - One of the best experts on this subject based on the ideXlab platform.
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Bearing capacity of geogrid reinforced sand over encased stone columns in Soft clay
Geotextiles and Geomembranes, 2017Co-Authors: Prasenjit Debnath, Ashim Kanti DeyAbstract:Abstract Stone columns develop their load carrying capacity from the circumferential confinement provided by the Surrounding Soils. In very Soft Soils, the circumferential confinement offered by the Surrounding Soft Soil may not be sufficient to develop the required load carrying capacity. Hence a vertical confinement would yield a better result. The load carrying capacity is further increased with the addition of a sand bed over the stone columns. In the present study, a series of laboratory model tests on an unreinforced sand bed (USB) and a geogrid-reinforced sand bed (GRSB) placed over a group of vertically encased stone columns (VESC) floating in Soft clay and their numerical simulations were conducted. Three-dimensional numerical simulations were performed using a finite element package ABAQUS 6.12. In the finite element analysis, geogrid and geotextile were modeled as an elasto-plastic material. As compared to unreinforced clay bed, an 8.45 fold increase in bearing capacity was observed with the provision of a GRSB over VESC. The optimum thickness of USB and GRSB was found to be 0.2 times and 0.15 times the diameter of the footing. A considerable decrease in bulging of columns was also noticed with the provision of a GRSB over VESC. Both the improvement factor and stress concentration ratio of VESC with GRSB showed an increasing trend with an increase in the settlement. It was observed that the optimum length of stone columns and the optimum depth of encasement of the group of floating VESC with GRSB are 6 times and about 3 times the diameter of the column respectively.
Jianhua Yin - One of the best experts on this subject based on the ideXlab platform.
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Responses of Excess Pore Water Pressure in Soft Marine Clay around a Soil–Cement Column
International Journal of Geomechanics, 2007Co-Authors: Zhen Fang, Jianhua YinAbstract:The Soil ground treated by deep cement mixing (DCM) in the field normally consists of cement–Soil mixed columns and untreated Soils. Although many attempts have been made, research on the consolidation behavior of the treated Soil ground has been limited. To better understand the consolidation process of the DCM treated ground, in this study, an axisymmetric physical model test with full instrumentation was carried out. The physical model ground consisted of a central cement–Soil column and Surrounding Soft Soil. Excess pore water pressures in the Soil and vertical pressures carried by the DCM column and the untreated Soil were recorded throughout the test. Responses of excess pore pressure under loading and unloading stages are highlighted. Based on the data analysis, it is revealed that the improved ground consolidates faster than the pure Soil ground. The major reason is considered to be that the DCM column reduces the vertical stress increment in the Soil and results in a lower value of excess pore pr...