Механіка деформування підсилених фундаментів за методом граничних елементів

Abstract

Deformation of soils under load is a complex process. This is due to the heterogeneity of the soil mass environment, complex geometric shapes of foundations, uneven loading on soils. Nonlinearity implies that the ratio between the components of the stress-strain state changes in the process of its change. It is very difficult to find accurate analytical solutions for predicting the stress-strain state of the soil. Problems of nonlinear soil deformation can be solved by numerical methods that allow avoiding the use of simplified assumptions that are accepted in analytical methods. The work is devoted to improving the methodology for calculating the stress-strain state of reinforced foundations using the modern numerical method of boundary elements (BEM) for the purpose of practical application, making decisions about their bearing capacity. Strengthening foundations is aimed at adapting them to trouble-free operation in variable operating conditions. When calculating the problem of the interaction of the foundation with the elastic medium, the solutions of R. Mindlin were used as the fundamental solution, since the pressure from the foundation in the soil is applied not to the soil surface, but at a certain depth inside the soil mass. When calculating, the boundary surface of the foundation was discredited by boundary elements, the active zone of the soil around the foundation was discredited by triangular cells. The calculation was carried out taking into account the dilatancy properties of the soil of the construction site and using the elastic-plastic model of the soil base. The topic of the work, which is devoted to the improvement of the computational and theoretical apparatus for designing reinforced foundations of structures, is relevant today. The application of BEM to the solution of a practical problem of geomechanics, the process of foundation settlement, and permissible loads on them is supported and illustrated by the data of the numerical calculation of reinforced columnar foundations of shallow foundation. As a result of the study, comparing the data of the numerical calculation and the full-scale experiment, the values of the bearing capacity of both reinforced and unreinforced foundations practically coincide.

Деформування ґрунтів під навантаженням являє собою складний процес. Це зумовлено неоднорідністю середовища ґрунтових масивів, складні геометричні форми фундаментів, нерівномірне навантаження на ґрунти. Нелінійність передбачає, що співвідношення між компонентами напружено-деформованого стану змінюється в процесі його зміни. Знайти точні аналітичні рішення для прогнозування напружено-деформаційного стану ґрунту дуже складно. Задачі нелінійної деформації ґрунтів можуть вирішуватися чисельними методами, які дозволяють уникнути застосування спрощених передумов, які приймаються в аналітичних методах.