This work introduces a theoretical framework for determining the active non-limit earth pressure of cohesive soil on a base-rotating rigid wall. The framework incorporates the nonlinear Mohr-Coulomb failure criterion, the Duncan-Chang hyperbolic stress-strain relationship, the log-spiral potential failure surface in retained soil, and a horizontal slice method for the earth pressure evaluation. The proposed method allows quantitative determination of displacement-dependent earth pressure and its distribution along the wall back. Practical wall movement in the at-rest state is considered, and the tension crack depth near the soil surface is calculated based on the soil tensile strength cut-off. Analysis results highlight the nonlinear variation of the mobilized soil shear strength vertically, influenced by the nonlinear Mohr-Coulomb failure criterion. As the wall rotation increases, the earth pressure follows a convex parabolic distribution with a tension failure zone near the soil surface and no pressure at the wall base. The resultant of the earth pressure reduces and its application point descends while the tension crack depth expands, though always remaining less than the Rankine's earth pressure. A practical example shows that the at-rest earth pressure can be up to 1.3 times greater than the active earth pressure, with the resultant application point approximately 5% higher. Parameter study exhibits that the active non-limit earth pressure correlates nonlinearly with the soil ultimate tensile stress and nonlinear coefficient, particularly as wall movement increases. Active non-limit earth pressures vary within 86% across different soil cohesions, and up to 50% under varying ultimate tensile stresses and nonlinear coefficients. Overturning safety factors of the wall in the active non-limit state differ significantly from those in the at-rest state, especially under varying soil cohesions.

Among various available methods for slope analysis, the limit equilibrium method is very popular because of its simple concepts. The limit analysis method and the finite element method (FEM) also can perform stability analysis of a slope. Increasing computing power and the easy accessibility of inexpensive numerical modeling codes have made the finite element method a very attractive tool for the practical assessment of slope stability. The present study reports the results of slope stability analysis of a few problems analyzed using a developed program utilizing FEM. This program employs a strength reduction technique based on FEM. Mohr-Coulomb strength criterion of soil is used for predicting the stress state, while the viscoplastic algorithm is used for stress redistribution. Non-convergence of the algorithm to achieve the desired equilibrium of all forces in the system is adopted as a marker of slope failure. Further, to put the proposed method to the test, a few examples from the literature are analyzed using the developed program. The example problems cover a homogenous slope with water loading, an inclined layered slope, and a staged embankment subjected to different forms of loading including earthquake forces, pore water pressure, external water pressure, etc. The results of each analysis are compared with other researchers work, and it is found that the obtained results are in good agreement. Deformed mesh, equivalent viscoplastic strain contour plots, and failure function contour plots are used for illustrating the failure state.

Granular piles, either ordinary or encased with geosynthetic materials are being extensively used as one of the ground improvement techniques, depending on the strength of the adjoining soil. The optimum granular pile (GP) length is still a matter of research, even though the approach is widely established in the literature. In the present study, a thorough and detailed parametric analysis has been carried out to ascertain the optimum length for ordinary and encased granular piles using a 2D axisymmetric finite element model. The soil behaviour has been modelled with the linearly elastic perfectly plastic Mohr-Coulomb failure criterion constitutive model. The parameters considered in this study are area replacement ratio, encasement stiffness, soil properties, infill material properties, and crust layer thickness. The findings revealed that the parameters with the greatest influence on the optimum length are the area replacement ratio, encasement stiffness, surrounding soil strength properties, and friction angle of the infill material. For encased granular piles, the optimum length was often found to be longer than ordinary granular piles. It was found that the optimum length for ordinary and encased GP ranges between 0.8-2.12 and 1-2.75 times of footing diameter (D), respectively. Through this study, an effort has also been made to investigate how the aforementioned parameters affect the radial bulging of the end-bearing GP. The upper of 0.5-1.5D showed excessive bulging in each case. Additionally, the optimum encasement length was determined, and it was found that increasing the encasement length beyond 1.5D results in minimal improvement. Furthermore, a multiple regression analysis was employed to establish the correlation between the optimum length of GP and potential influencing factors.