BOUNDARY ELEMENT METHOD IN THE MECHANICS OF GRANULAR SOIL MEDIA

Abstract

The article presents a comprehensive approach to modeling the behavior of a bored pile in a nonlinear soil foundation using the numerical boundary element method (BEM). Considering the complex nature of soils as a dispersed medium, the study accounts for elastic-plastic properties and dilatancy effects under shear loading. The main focus is on formalizing the transition of soil into a plastic state based on the non-associated flow rule and the Mises–Schleicher–Botkin yield criterion. The computational model includes 28 parameters, of which 10 are physical and mechanical properties of the soil, while the rest define the geometry and discretization of the pile. The application of this model allows for accurate prediction of the stress-strain state at each loading stage, taking into account local inhomogeneities and structural changes in the soil. The numerical implementation is based on R. Mindlin’s fundamental solutions for boundary conditions and includes an iterative step-by-step loading algorithm following O. A. Illyushin’s method. A comparative analysis of numerical modeling results with experimental data and regulatory calculations showed satisfactory agreement. The presented approach is of significant importance for improving the accuracy of engineering calculations in the design of pile foundations on weak and heterogeneous soils.