Numerical study of the convergence of methods for determining bed coefficients under different geological conditions of the base

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Iryna Zhupanenko

Abstract

Despite the significant development of numerical modeling of the joint work of above-ground structures with the ground base, today the most popular in the community of design engineers is the calculation model of the slab on an elastic basis.
This is primarily due to the simplicity of the implementation of such a model and the possibility of a comprehensive calculation of the base-foundation system.
The key step in calculating the model of the slab on an elastic basis is to determine the coefficients of flexibility of the base.
In this paper, with the help of software and computer system LIRA CAD 2016 conducted a study of methods for determining the stiffness coefficients of the bed under different variants of soil conditions.
The study was implemented by numerical analysis of the characteristics of the stress-strain state (the amount of subsidence, reactive pressure and force) in a square in terms of evenly loaded foundation slab under different engineering and geological conditions of the construction site.
Considered:
1) homogeneous in plan base, composed of a finite number of linearly deformed layers of constant thickness;
2) homogeneous in plan base, composed of layers of constant thickness, one of which is a loess subsidence;
3) inhomogeneous base, composed of alternating layers of cohesive and incoherent soils, one of which is not constant in thickness.
The convergence of the absolute values of the controlled parameters obtained for the model with two stiffness coefficients (Pasternak model), which for multilayer soils are determined by the values of the modulus of deformation and Poisson's ratio averaged within the depth of compressible thick-ness and for the model with one variable in terms stiffness coefficient (Gorbunov-Posadov model).
The results of the study show that the scope of the two-parameter Pasternak model (which is more correct than the one-parameter Gorbunov-Posadov model) is limited to a homogeneous single- or multilayer soil base, provided that the soil layers are of constant thickness. Instead, the Gorbunov-Posadov model allows to calculate inhomogeneous bases and soils with special properties (sieving). However, this model does not allow to take into account the spatial work of the soil and the mutual influence of load areas.

Article Details

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Author Biography

Iryna Zhupanenko, Kyiv National University of Construction and Architecture

Associate Professor of the Department of Resistance of Materials

References

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