Models of deformation behavior and analytical methods for determining settlement of weak soils

Abstract

The main safety requirements for the subgrade of fast and high-speed highways on weak foundations are to ensure a given level of stability and resistance, limit the magnitude and rate of consolidation of weak soils, taking into account the dynamics of loads during high-speed train traffic. The numerical modeling method, in particular, the finite element method in conjunction with the classical problem of Tertsagi-Gersevanov filtration consolidation, seems to be the most promising for solving the tasks. Based on the analysis of a set of prerequisites and initial data for modeling and calculating the consolidation of a weak foundation reinforced with pile structures, it is shown that using an ideal elastic-plastic model and a hardening soil model, the problems of determining the conditions for the effective operation of a pile composite structure, as well as modeling, calculating and assignment of design parameters of a pile composite structure can be solved. To take into account the specifics of the consolidation of waterlogged clay soils, the corrected Tertsagi-Gersevanov filtration consolidation equation is proposed, taking into account the change in soil porosity during its compaction. It is assumed that under a single loading (or unloading), the relationship between stresses and strains in soils is linear. At present, quite a lot of experimental data has been accumulated that contradicts the theory of linear soil deformation.