Within the framework of the urban environment, the laws of distribution of the concentration of fine dust PM2.5, PM10 along road sections have been obtained. These data are necessary to assess the probability of exceeding the maximum permissible concentrations and to improve monitoring and control systems for atmospheric air. The analysis of the key factors influencing the content of PM2.5 and PM10 particles in the air of the territories adjacent to the roads has been carried out. Regression equations for total dust, PM2.5 and PM10 dust were obtained, allowing us to conclude that the concentration of PM2.5 and PM10 depends on total dust. The analysis showed that the mass content of PM10 in total dust pollution ranges from 73 to 81%, and the concentration of fine dust PM2.5 varies within two narrow ranges of about 11.6 and about 7 microns. A study of the proportion of PM2.5 of the total concentration showed that it is on average about 20%.

Keywords: dust, emissions, concentration, atmospheric air, roadway, climate, linear city, correlation coefficient, influencing factors

Changes in the elastic characteristics of the soil for a base model that is inhomogeneous in depth are considered. The dependences of the modulus of elasticity of the soil and the coefficient of lateral pressure on the relative depth are obtained.

Keywords: modulus of elasticity, lateral pressure coefficient, pressure, compression curve

The cases of uneven compression of a concrete cylinder in the case of simple loading and comprehensive uneven compression of a spiral-reinforced concrete cylinder under disproportionate loading are considered. The dependences of longitudinal, transverse and volumetric deformations on longitudinal stress are obtained.

Keywords: longitudinal stress, circumferential stress, longitudinal deformation, circumferential deformation, spiral reinforced concrete strut, shear strain intensity, shear stress intensity

The paper is concerned with relevant stress concentration research in construction elements made of structurally heterogeneous materials. On the base of the physico-mechanical model of structurally heterogeneous body (polycrystal) , with the use of finite elements method, stress distribution in construction elements made of polycrystalline metals with hexagonal lattice (magnesium, titanium, zinc) is investigated at various stress states. Coefficients of stress concentration in plates with circular holes are determined in the case of uniaxial tension, uniform biaxial tension, and pure shear. It is demonstrated that stress concentration coefficients calculated regarding microstructural factors of stress concentration can take values that considerably differ from values for isotropic body, depending on anisotropy of elastic properties of polycrystalline metals and a type of stress state

Keywords: linear and plane stress states, polycrystalline structure, microstructural factors, nonuniformity of stress

The paper deals with the results of study on the degrees of stress inhomogeneity caused by interaction between differently oriented crystalline grains in macrovolumes in case of non-uniform uniaxial tension. Calculation of finite element volume consisting of forty grains is performed. It has been revealed that the quantity of forty grains is enough for constituting the smallest body volume, which can be assumed to have the averaged properties of a macrovolume. Directions of crystallographic axes were selected randomly. Calculations were performed for various metals with cubic and hexagonal lattices. Based on the results of calculations, the curves of normal stresses in the central cross-section of the elementary volume were constructed. It has been found that the significant exceedance of normal stress values is possible in comparison to the values calculated for quasi-isotropic fine-grain material. Dependence between the degree of stress inhomogeneity and the degree of anisotropy of elastic properties has been demonstrated

Keywords: microvolume, macrovolume, non-uniform tension, degree of stress inhomogeneity

Structurally heterogeneous materials, in particular polycrystalline materials, have wide application in construction and technics. The higher values of local microstress in comparison to the average values of stress lead to the faster exhaustion of bearing capacity and destruction. Therefore, nonuniformity of microstress and microstrain depending on structure, physical and mechanical properties, should be taken in consideration when estimating bearing capacity, especially for the elements of construction with different stress concentrators. On the base of the physico-mechanical model of structurally heterogeneous body stress concentration for small-scale plates , made of polycrystalline materials with hexagonal lattice, with circular holes, at the case of uniaxial stress state, is investigated. It is shown that coefficients of stress concentration depending on anisotropy of elastic properties of polycrystalline materials can take values which considerably differ from values for isotropic body. Physico-mechanical model developed for structurally heterogeneous body allows studying local microstress in the construction elements at various stress states, with different forms and kinds of stress concentrators, which is the subject of the further research

Keywords: stress distribution, structural heterogeneity of the material, polycrystalline metals,microstress and microstrain, stress concentration

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