ABSTRACT
The physical nonlinearity of soil deformation distinguishes it from the deformation of structural materials, as the stiffness characteristics of soil depend on the stress-strain state. Therefore, determining the mechanical parameters of soils requires considering the in-situ stress conditions. This article presents an in-situ method for determining these parameters for a phenomenological physically nonlinear soil model. The method also allows for determining the characteristics of an elastic-plastic model with the Coulomb flow condition. The use of this method for designing foundations on non-rocky soils (sand, clay) can significantly reduce costs while ensuring reliability. The method is based on special procedures for solving inverse nonlinear problems through numerical simulation of soil deformation under static loading. It also takes into account the geometric nonlinear factor of comparability of one-dimensional and angular deformations in non-rocky soils. The core idea of the method is to minimize the deviations between actual soil deformations from in-situ tests and numerically simulated deformations using a verified physically nonlinear soil model. The application of this method in the design of a spread-slab foundation for a high-rise residential building in Ekaterinburg (Russia) resulted in a one million USA dollars cost reduction while maintaining the necessary foundation reliability. This was achieved by using a physical and mathematical soil model that accurately represents the nonlinear deformation behavior of the soil and incorporates the actual values of soil mechanical parameters. The article includes the algorithm of the method and provides examples of its practical application in the design of real projects.
