The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Suraparb Keawsawasvong - One of the best experts on this subject based on the ideXlab platform.
-
Failure Modes of Laterally Loaded Piles Under Combined Horizontal Load and Moment Considering Overburden Stress Factors
Geotechnical and Geological Engineering, 2020Co-Authors: Suraparb Keawsawasvong, Boonchai UkritchonAbstract:A large number of studies on various aspects of laterally loaded piles in clay have been conducted in the literature based on experimental and numerical analyses; however, the lack of studies on the influence of the soil unit weight on the undrained capacity of the problem is obvious. In this paper, the effects of the Overburden Stress factors on the undrained capacity of laterally loaded piles under combined horizontal load and moment are comprehensively investigated by employing the three-dimensional (3D) finite element analysis. In the present study, soil–pile interfaces are modelled as the no-tension condition while the influences of the pile length ratios are also examined in the numerical analyses. The failure envelopes of laterally loaded piles under combined horizontal load and moment incorporating Overburden Stress factors, pile length ratios are presented. Employing the normality rule to the derived failure envelopes, the failure mechanisms corresponding to the ratio between applied moment and horizontal load are postulated in this paper. An approximate solution of the failure envelope of laterally loaded piles is also proposed by using a nonlinear regression analysis, and provides a convenient tool for predicting the undrained lateral capacity of piles considering Overburden Stress factors in practice.
-
Stability of Retained Soils Behind Underground Walls with an Opening Using Lower Bound Limit Analysis and Second-Order Cone Programming
Geotechnical and Geological Engineering, 2019Co-Authors: Boonchai Ukritchon, Suraparb KeawsawasvongAbstract:Lower bound finite element limit analysis in conjunction with second-order cone programming is developed and employed to investigate the stability of retained soils behind underground walls with an opening in cohesive-frictional soils. In this study, two-dimensional plane strain condition is setup for modelling the problem while the lower bound solution of the problem is obtained by employing the finite element approach of lower bound limit analysis. The lower bound optimization problem is cast as the second-order cone programming, and is solved by a conic programming algorithm. For practical use, the results of lower bound solution are summarized in the form of dimensionless stability charts of the load factor that is a function of the cover depth ratio of opening, Overburden Stress factor and soil friction angles. Plastic yielding zones predicted from the lower bound analysis are discussed and examined for these dimensionless parameters while the computed lower bound solutions are validated with an existing solution. Finally, a closed-form approximate expression is developed for predicting the lower bound solution of the load factor for the problem with practical ranges of cover depth ratios of opening, Overburden Stress factors, and soil friction angles. New opening stability factors with respect to soil cohesion and unit weight as a function of cover depth ratios of opening and soil friction angles are presented.
-
three dimensional undrained tunnel face stability in clay with a linearly increasing shear strength with depth
Computers and Geotechnics, 2017Co-Authors: Boonchai Ukritchon, Kongkit Yingchaloenkitkhajorn, Suraparb KeawsawasvongAbstract:Abstract The undrained tunnel face stability in clay with a linearly increasing shear strength with depth was investigated by three-dimensional finite element analysis. Three parametric studies were performed to study the effects of the cover depth ratio, Overburden Stress factor and linear strength gradient ratio on the load factor of the undrained tunnel face stability. The influence of the linear strength gradient ratio on the predicted failure mechanism of the undrained face stability was discussed and examined. An approximate closed-form solution was proposed for three-dimensional undrained tunnel face stability in clays with constant or linearly increasing shear strength profiles with depth.
-
Design equations for undrained stability of opening in underground walls
Tunnelling and Underground Space Technology, 2017Co-Authors: Boonchai Ukritchon, Suraparb KeawsawasvongAbstract:Abstract Undrained stability of an opening in underground walls in clays with constant and linearly increasing shear strengths with depth was investigated by two-dimensional finite element limit analysis under plane strain condition. Three parametric studies were performed to study the effects of the cover depth ratio, Overburden Stress factor and linear strength gradient ratio on the load factor of the opening in underground walls. Predicted failure mechanisms associated with these parameters were discussed and examined. New design equations for the undrained stability of an opening in underground walls in clays with an arbitrary linear increase in strength with depth were developed for a practical application in the field of trenchless constructions.
Boonchai Ukritchon - One of the best experts on this subject based on the ideXlab platform.
-
Failure Modes of Laterally Loaded Piles Under Combined Horizontal Load and Moment Considering Overburden Stress Factors
Geotechnical and Geological Engineering, 2020Co-Authors: Suraparb Keawsawasvong, Boonchai UkritchonAbstract:A large number of studies on various aspects of laterally loaded piles in clay have been conducted in the literature based on experimental and numerical analyses; however, the lack of studies on the influence of the soil unit weight on the undrained capacity of the problem is obvious. In this paper, the effects of the Overburden Stress factors on the undrained capacity of laterally loaded piles under combined horizontal load and moment are comprehensively investigated by employing the three-dimensional (3D) finite element analysis. In the present study, soil–pile interfaces are modelled as the no-tension condition while the influences of the pile length ratios are also examined in the numerical analyses. The failure envelopes of laterally loaded piles under combined horizontal load and moment incorporating Overburden Stress factors, pile length ratios are presented. Employing the normality rule to the derived failure envelopes, the failure mechanisms corresponding to the ratio between applied moment and horizontal load are postulated in this paper. An approximate solution of the failure envelope of laterally loaded piles is also proposed by using a nonlinear regression analysis, and provides a convenient tool for predicting the undrained lateral capacity of piles considering Overburden Stress factors in practice.
-
Stability of Retained Soils Behind Underground Walls with an Opening Using Lower Bound Limit Analysis and Second-Order Cone Programming
Geotechnical and Geological Engineering, 2019Co-Authors: Boonchai Ukritchon, Suraparb KeawsawasvongAbstract:Lower bound finite element limit analysis in conjunction with second-order cone programming is developed and employed to investigate the stability of retained soils behind underground walls with an opening in cohesive-frictional soils. In this study, two-dimensional plane strain condition is setup for modelling the problem while the lower bound solution of the problem is obtained by employing the finite element approach of lower bound limit analysis. The lower bound optimization problem is cast as the second-order cone programming, and is solved by a conic programming algorithm. For practical use, the results of lower bound solution are summarized in the form of dimensionless stability charts of the load factor that is a function of the cover depth ratio of opening, Overburden Stress factor and soil friction angles. Plastic yielding zones predicted from the lower bound analysis are discussed and examined for these dimensionless parameters while the computed lower bound solutions are validated with an existing solution. Finally, a closed-form approximate expression is developed for predicting the lower bound solution of the load factor for the problem with practical ranges of cover depth ratios of opening, Overburden Stress factors, and soil friction angles. New opening stability factors with respect to soil cohesion and unit weight as a function of cover depth ratios of opening and soil friction angles are presented.
-
three dimensional undrained tunnel face stability in clay with a linearly increasing shear strength with depth
Computers and Geotechnics, 2017Co-Authors: Boonchai Ukritchon, Kongkit Yingchaloenkitkhajorn, Suraparb KeawsawasvongAbstract:Abstract The undrained tunnel face stability in clay with a linearly increasing shear strength with depth was investigated by three-dimensional finite element analysis. Three parametric studies were performed to study the effects of the cover depth ratio, Overburden Stress factor and linear strength gradient ratio on the load factor of the undrained tunnel face stability. The influence of the linear strength gradient ratio on the predicted failure mechanism of the undrained face stability was discussed and examined. An approximate closed-form solution was proposed for three-dimensional undrained tunnel face stability in clays with constant or linearly increasing shear strength profiles with depth.
-
Design equations for undrained stability of opening in underground walls
Tunnelling and Underground Space Technology, 2017Co-Authors: Boonchai Ukritchon, Suraparb KeawsawasvongAbstract:Abstract Undrained stability of an opening in underground walls in clays with constant and linearly increasing shear strengths with depth was investigated by two-dimensional finite element limit analysis under plane strain condition. Three parametric studies were performed to study the effects of the cover depth ratio, Overburden Stress factor and linear strength gradient ratio on the load factor of the opening in underground walls. Predicted failure mechanisms associated with these parameters were discussed and examined. New design equations for the undrained stability of an opening in underground walls in clays with an arbitrary linear increase in strength with depth were developed for a practical application in the field of trenchless constructions.
Kerry R Rowe - One of the best experts on this subject based on the ideXlab platform.
-
water retention of geosynthetics clay liners dependence on void ratio and temperature
Geotextiles and Geomembranes, 2019Co-Authors: Ali Ghavamnasiri, Abbas Elzein, David Airey, Kerry R RoweAbstract:Abstract The dependence of the geosynthetic clay liners (GCLs) soil-water characteristic curve (SWCC) on temperature and Overburden Stress are characterised experimentally. It is shown that changes in void ratio and temperature alter the relationship between suction and moisture content and new forms of existing SWCC equations are developed. To cover a wide suction range, the SWCCs are measured using axis-translation and dew point methods. Based on the available experimental data, both proposed SWCCs are shown to perform well in predicting the effects of void ratio on SWCC along the drying path when compared to the experimental results. It is found that the air-entry value increases as the net vertical Stress increases for the experiments under the same temperature. In addition, elevation of temperature reduces retention capacity of the GCL.
Allen L. Zack - One of the best experts on this subject based on the ideXlab platform.
-
The effects of Overburden Stress on the specific storage and hydraulic conductivity of artesian aquifers
Journal of Hydrology, 1991Co-Authors: Nicasio Sepúlveda, Allen L. ZackAbstract:Abstract A mathematical algorithm is developed to determine the depth-dependent profiles of specific storage and hydraulic conductivity resulting from Overburden Stress in horizontally isotropic artesian aquifers. Vertical variations in the void ratio of the aquifer matrix brought about by Overburden Stresses determine the pore-volume compressibility and matrix permeability at specific depths within the aquifers which, in turn, determine the depth-dependent profiles of specific storage and hydraulic conductivity. Time-drawdown curves are obtained for two sands subjected to different Overburden Stresses. For shallow artesian aquifers with low Overburden Stress and high aquifer matrix compressibility, noticeable vertical gradients in specific storage occur. These vertical gradients cause deviations from the classical time-drawdown curves defined by the Theis solution. These deviations are negligible for deep artesian aquifers.
Ali Ghavamnasiri - One of the best experts on this subject based on the ideXlab platform.
-
water retention of geosynthetics clay liners dependence on void ratio and temperature
Geotextiles and Geomembranes, 2019Co-Authors: Ali Ghavamnasiri, Abbas Elzein, David Airey, Kerry R RoweAbstract:Abstract The dependence of the geosynthetic clay liners (GCLs) soil-water characteristic curve (SWCC) on temperature and Overburden Stress are characterised experimentally. It is shown that changes in void ratio and temperature alter the relationship between suction and moisture content and new forms of existing SWCC equations are developed. To cover a wide suction range, the SWCCs are measured using axis-translation and dew point methods. Based on the available experimental data, both proposed SWCCs are shown to perform well in predicting the effects of void ratio on SWCC along the drying path when compared to the experimental results. It is found that the air-entry value increases as the net vertical Stress increases for the experiments under the same temperature. In addition, elevation of temperature reduces retention capacity of the GCL.
