Ensuring the stability of slopes is critical to the safe operation of geotechnical engineering. Evaluating slope stability to minimize geologic risks induced by destabilization is significant in reducing casualties and property damage. A conventional, single-coefficient strength reduction method is widely applied in slope stability analyses, but this method ignores the attenuation degree of different parameters in the slope destabilization. A new double-strength reduction method considering different contributions of the mechanics' parameters is proposed in this study for evaluating the stability of nonhomogeneous slope. First, the role of each mechanic's parameters in the slope destabilization was investigated theoretically and numerically using ABAQUS software 2022. The results indicate that the effect of elasticity (E), Poisson's ratio (v), and soil gravity (gamma) on the evolution of factor of safety (FOS) are insignificant and can be neglected compared with cohesive force (c), and angle of internal friction (phi). Next, an improved method was constructed to correlate the FOS with cohesive force (c) and the angle of internal friction (phi). Then, a numerical method was constructed based on the computation of the mathematical-mechanical relationship between FOS and the mechanical parameters, and the stability of slope is estimation based on the Mohr-Coulomb yield criterion. Finally, the double-strength reduction coefficient method proposed in this study, the limit equilibrium method, and the traditional finite element strength reduction coefficient method were applied to nonhomogeneous slopes and slopes containing a soft underlying layer for comparison, and the difference between them was within the range of +/- 5%. The results indicate that both the limit equilibrium method and the traditional finite element strength reduction method tend to overestimate the FOS of intricate slopes compared with the evaluated method proposed in this study. This parallel comparison serves to validate the accuracy of the double-strength reduction method proposed in the present study. Further, based on the proposed method, the relationship between slope stability and slope displacement is established, which provides a theoretical basis for the safety assessment of slope engineering.

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.

A landslide is a common natural disaster that causes environmental damage, casualties and economic losses, which seriously affects the sustainable development of society. In geomechanics, it is one of the largest deformation problems. Herein, the GPU-accelerated explicit smoothed particle finite element method (eSPFEM) for large deformation analysis in geomechanics was developed on the CUDA platform based on high-performance computing using a self-designed eSPFEM program code. The eSPFEM combines the strain smoothing nodal integration techniques found in the particle finite element method (PFEM) framework, which allows for the use of low-order triangular elements without volume locking and avoids frequent information transfer and mapping errors between Gaussian points and particles in PFEM. A numerical simulation of slope instability using the eSPFEM and based on a strength reduction technique was conducted using various examples, including a cohesive homogeneous slope, a non-cohesive homogeneous slope, a non-homogeneous slope and a slope with a thin soft band. The calculation results show that the eSPFEM can be applied to slope stability analysis under different working conditions, simulating the entire process of slope instability initiation, sliding and reaccumulation, and obtaining reliable FOS values. A numerical simulation was conducted to analyse a landslide that occurred in the Zhangjiazhuang tunnel on the Lanzhou-Xinjiang high-speed railway line on 18 January 2016. A natural unsaturated soil slope, a soil slope with a high moisture content and a soil slope with a high moisture content subjected to an earthquake were analysed. The findings of this study are in good agreement with the actual slope failure conditions. The primary triggers identified for the landslide were heavy rainfall and earthquakes. The verification results indicate that the eSPFEM can effectively simulate an actual landslide case, showcasing high accuracy and applicability in simulating the large deformation behaviour of landslides.