THEORETICAL CALCULATION OF REINFORCED FOUNDATIONS TAKING INTO ACCOUNT ANISOTROPY OF SOILS

Abstract

The introduction of horizontal reinforcing elements into the soil, which have much higher deformation rates in the longitudinal
direction, turns it into an anisotropic medium. That is, an environment in which the strength characteristics in the vertical and
horizontal directions are significantly different.
This article considers the case when the reinforcing elements are laid horizontally, and their thickness is much smaller than
the thickness of the soil layers, so it can be neglected and the characteristics of the strength and deformations of the reinforced
soil in the horizontal direction can be taken as for unreinforced. In the vertical direction, the presence of reinforcement in the soil
mass significantly changes its characteristics. This is confirmed by the obtained results of model tests.
The calculation of reinforced foundations is reduced mainly to the determination of the influence of reinforcement parameters
on the distribution of stresses and, accordingly, deformations in the layers of reinforced soil.
The solution is based on the basic formulas of the stress state of an anisotropic half-plane loaded with a linear load. The base
is represented by a linearly deformable porous medium, the state of which is characterized by the deformation moduli Еx, Ez, the
Poisson coefficients νx, νz and the shear modulus Gz.
We introduce the assumption that along the entire length of the horizontal reinforcing element, the tangential stresses in the
soil retain their maximum values max  . Such stresses should be taken into account within the scope of influence of the reinforcing
element [2-3], which is included in the margin of strength.
Obtained expressions of the maximum tangential and principal stresses of the reinforced soil, taking into account the
anisotropic medium.
The dependence of the selection of the cross-section of reinforcing elements of soil foundations on the calculated resistance
of the materials used for them is determined.
Calculated dependences of the modulus of deformation of reinforced bases in the vertical direction Ez, due to the length of
the reinforcement and the reinforcement step, were obtained.
The shear modulus Gz of anisotropic reinforced soils is determined, taking into account the parameters of the reinforcement,
as well as the anisotropic properties of the soil.