The finite-element three-dimensional array of soil – as a tool for modeling influences in forecasting changes in the stress-strain state of building structures

Abstract

There is about 85% of the territory of Ukraine is composed of certain engineering and geological conditions, which are generally classified as a difficult for building and operation of buildings and structures. These conditions include loess subsidence and structurally unstable soils, floodplain sections of rivers with the presence of weak muddy soils. A lot of building objects during the operation are subjected to deformation effects on the part of the base, which leads to an uneven draft, and as a result, to a change in the stress-strain state of the structures, and in some cases to a change in the nature and working conditions of individual structures and redistribution of stresses in them.

It is recommended to perform verification and predictive calculations to ensure reliable and trouble-free operation of buildings and structures at all stages of the life cycle under difficult engineering and geological conditions, especially in the case of preconditions for the development of uneven sediments of the base. These calculations, which produced by certain algorithms and methods, allows to track, analyze and predict changes in the stress-strain state of building structures.

The article discusses of possible options for accounting the soil foundation, implemented in LIRA-Windows, as well as justifying the choice of modeling the foundation in the form of a three-dimensional soil massif using FE No.34 and FE No.36 in a linear formulation.

There are considered main existing methods of computer modeling of the soil foundation. And there is substantiated the expediency of using a three-dimensional array of soil in a linear formulation in the calculations of the «base-foundation-building» system.

The model of an elastic half-space of a ground base in the form of a three-dimensional array is allows to perform verification calculations of buildings and structures at all stages of their life cycle, as well as in forecasting; also it meets all requirements of current normative documents and tested in practice, has a sufficient level of adequacy and compliance with the actual survey data; for a certain class of problems, it allows not to take into account the physical nonlinearity of the soil base.