The technology of organizing the construction of decentralized energy systems based on wind power plants is given. New design solutions for the structural elements of wind turbines and overhead lines (tower, collapsible ballast-type foundation, protective element) are proposed, taking into account the specifics of the technology of construction and installation works. Data are given on reducing the cost of construction production by optimizing the machines and mechanisms used.

Keywords: wind turbine structures, overhead lines, tower, collapsible ballast-type foundation, protective element, in-line method, decentralized system

The optimization of the taxable base of capital construction objects is considered, this is the desire of customers and operating organizations to manage the cost of ownership of one or another technical solution, which is certainly reasonable in modern conditions, when when making a technical solution, its full cost is estimated, including the so-called cost of ownership for the entire period of the life cycle of the object, from the formation of an idea for the creation of a future object to its decommissioning.

Keywords: collapsible foundation, protective element, flow method, wind power plant, building structures

The analysis of the experimental data is carried out and the works devoted to the account of the influence of the compressive pressure factor with the purpose of optimizing the parameters of the centrifuged products of the annular section at the compaction stage are studied. The number of rotations of the mold at the compaction stage is calculated for different values of the compressive pressure. A statistical analysis of the regression equations obtained is performed using three criteria: homogeneity of variances, significance of coefficients and adequacy, which was tested with the help of Fisher's criterion. The data were statistically processed using the Mathcad program, which allowed obtaining regression equations in the form of polynomials of the second degree with specific values of their coefficients. Graphic interpretation of mathematical dependencies is constructed. The calculated dependencies are obtained that allow to determine the required number of revolutions for any required diameter and wall thickness of annular centrifuged products for a given fixed value of the compressive pressure in concrete.

Keywords: compressive pressure, centrifuged products of annular section, response function, factor of variation, least squares method, regression equation

A review of the literature concerning the molding of centrifuged concrete products was carried out. The peculiarities of centrifugation of concrete, in particular, the manufacture of centrifuged pipes, have been studied. The main parameters and indices of the quality of concrete and the centrifuged tubes themselves are considered. The traditional mode of forming non-pressure pipes is described. The calculation formulas for the parameters of the centrifugation process and their graphical dependences are given. Based on the calculated data, it is concluded that the traditional modes of shaping of non-pressure pipes are characterized by the rotation speed of the mold from 82 to 300 rpm in the stages of loading and distribution of the concrete mixture. At the sealing stage, the control of the rotation speed of the mold varies over a very wide range and depends largely on the viscosity of the concrete mix and the pressing pressure: from 825 to 4400 rpm for concrete pipes with a diameter of 100 to 300 mm. Modeling the parameters of the molding regime during the centrifugation of ring-shaped products in a laboratory installation at a maximum compaction pressure of p = 2.16 kg/cm2 will allow us to refine the obtained data and study their effect on the variability of the concrete structure

Keywords: centrifugal force, centrifugation parameters, charging speed of the mold, speed distribution of the shape, sealing speed of the mold, pressing pressure, centrifugation time, ring-shaped products

We investigated the creep of concrete arches based on the following theories: the theory of linear creep by Harutyunyan-Maslov, kinetic theory, the theory of flow, theory of aging, and nonlinear theory of Y. Gurieva. We considered viscoelastic model of the concrete, ie total strain was represented as the sum of elastic strain and creep strain. Solution of the problem was carried out by finite element method. We considered the arch rigidly clamped at the ends and loaded with a uniformly distributed load. Graphs of growth of deflection and stress distribution in the reinforcement and concrete are represented. We obtained the substantial redistribution of stress between the reinforcement and the concrete during creep: in reinforcement stresses increased and in concrete stresses decreased. The strongest redistribution occurs on the theory Y. Gureva.

Keywords: reinforced concrete arch, creep theory of heredity, aging theory, the theory of flow, kinetic theory, finite element method, stress-strain state

The phenomenon of buckling under the creep of concrete arches was investigated. Solution of the problem carried out by means of the finite element method. To analyze the stability we used Newton-Raphson method. It has been established that there is a long-term critical load, beyond which the growth of the deflection has not fading character. As the equation of the relationship between the creep deformation and strains we used viscoelastoplastic hereditary model of aging concrete. To determine the creep strain we used a linear approximation with respect to time. It was found that the long critical load for considered arch was in 1.44 times lower than the instant critical load.

Keywords: reinforced concrete arch, stability, creep, geometric nonlinearity, finite element method, Newton-Raphson method