Analysis of a soil slope stability based on modified failure criterion

Purpose. To analyze the stability of soil slopes based on the proposed modified failure criterion, numerical modeling, and laboratory soil tests. The primary focus is on determining the influence of the physical and mechanical properties of soils on slope instability. The research is aimed at improving landslide prediction methods and developing approaches for integrating laboratory data into numerical models to enhance their accuracy. Methodology. The study employs a comprehensive set of research methods, including laboratory testing of loam and sandy loam soil samples to determine their mechanical properties, analytical derivation of the soil failure criterion, finite element modeling of the stress-strain state of the soil slope, and correlation analysis of factors influencing slope stability. Findings. The mechanical properties of loam and sandy loam soils were obtained. A modification of the Coulomb-Mohr criterion was proposed, which accounts for changes in soil strength parameters (cohesion and internal friction angle) depending on the stress state of the soil massif. A multifactor finite element stability analysis of the soil slope, based on the proposed criterion and conducted using the Phase2 software, enabled the development of relationships between the safety factor and the strength and geometric parameters of the slope. Originality. A new approach to evaluating the strength characteristics of loam and sandy loam soils is proposed, serving as a compromise between the linear Coulomb-Mohr criterion and the nonlinear criterion of O. Shashenko. This approach allows for consideration of the initial stress state of the soil massif ‒ whether of natural or technogenic slope origin. The influence of variations in internal friction angle and cohesion on slope stability was determined through numerical modeling, enabling improved accuracy in predicting deformation processes within the soil massif. Practical value. The application of the proposed approach enhances the accuracy of predicting the mechanical behavior of soil massifs, contributing to the reduction of landslide risks and deformation of engineering structures. Numerical modeling in the Phase2 environment can be implemented in design practice to optimize foundations and reinforce soil bases. The obtained results can be used to assess the safety of engineering structures built on potentially unstable sites, as well as to optimize design solutions in construction.