Vol. 26, Number 4, 2020

Vladimir Anishсhenkov, Andrey Mironov, Dmitry Alekseyev
Method of Experimental Studies of Frame Pipe-Concrete Units with Round-Tube Struts and I-beam Crossbars
Donbas National Academy of Civil Engineering and Architecture
Abstract. The article provides a method for conducting static tests of a pipe-concrete unit. In the form of a column, a circular pipe with a diameter of 220 mm and a wall thickness of 7 mm was used, the length of a column fragment was 1 050 mm. The pipe is filled with concrete of class B15. As crossbars, a steel I-beam № 20 with a cantilever overhang of 1 100 mm is used. The joining of the crossbars to the column is ensured by two horizontal and four vertical plates 5 mm thick by welding. The load on the tube of the unit was transferred by a PMM-250 press. The load on the girders was transferred by hydraulic vehicle jacks with a lifting capacity of 20 tons through a compression dynamometer. The step of applying the load for the experimental model on the struts is 20 tons, on the crossbars – 0,5 tons each (a total of 10 loading steps). The holding time of each stage is 3 minutes (for the perception and distribution of the load in the structure). The readings from the strain gages were recorded using the SIIT-3 measuring strain gauge system with a record in the test log. The results of experimental studies will make it possible to determine the convergence of the parameters of the stress-strain state (SSS) with the results of numerical studies.
Keywords: frame assembly, strain gauge, hydraulic press, strain gauge system, compression dynamometer, calibration beam, compensation strain gauge, experimental model.

Natalia Smirnova, Andrey Mironov
Methods of Eperimental Studies of the Anchor Support U220+9 with Imperfections under the Action of Static Loads
Donbas National Academy of Civil Engineering and Architecture
Abstract. The article presents the method of testing the U220+9 anchor-angle support with imperfections at the DNAСА test site. To compare the VAT indicators of the support elements, two load tests of the support were carried out according to similar schemes. During the first test, the support was loaded without imperfections. During the second load test, the situation of the formation of a general curvature of the grid elements from the plane of the support face was simulated. Tests with imperfections were carried out in two stages. At the first stage, the behavior of individual elements and support units in the process of defect formation in the form of a general curvature of the rod from the plane of the structure is considered. At the second stage, the response of the studied structure to the defective rod was analyzed. The above test procedure allowed us to determine: the locations of strain-measuring studies to analyze the response of the structure under study to a rod with extreme deformation; the load-bearing capacity, according to the criteria of strength and stability, corresponding to the first group of limit states; operational suitability of the structure as a whole when working with imperfections.
Keywords: anchor-angular support, polygon, technique, static tests, curvature, work of structures with imperfections, strain-measuring studies.

Igor Romenskii a, Andrey Mironov a, Roman Piletskiy b
Stress-Strain State of the Protective Wall of a Steel Vertical Cylindrical Tank under the Influence of Hydrodynamic Shock due to Emergency Situations
a Donbas National Academy of Civil Engineering and Architecture, b Ministry of Civil Defense, Emergencies and Elimination of Consequences of Natural Disasters of the Donetsk People’s Republic
Abstract. The article discusses approaches that increase the reliability and safety of operation of steel vertical cylindrical tanks. A constructive solution in the form of an additional protective wall is substantiated. This ensures environmental safety and minimizes the consequences of accidents associated with the violation of the integrity of the main wall of the tank and the outflow of all stored liquid within a short period of time. A spatial design model of a reservoir with a protective wall in the Lira PK is proposed. The parameters of the emergency hydrodynamic load acting on the protective wall of the tank are determined. The results of the study of the influence of hydrodynamic load on the stress-strain state of the protective wall are presented. Significant stresses and deformations exceeding the regulatory requirements were determined. Solutions to improve the design of the protective wall are proposed. The installation of an upper strapping and several tiers of stiffening rings, as well as an increase in the thickness of the supporting part of the bottom, ensure the strength and stability of the protective wall when exposed to a hydrodynamic shock load.
Keywords: steel vertical cylindrical tank, protective wall, stress-strain state, quasi-instantaneous failure, hydrodynamic shock, emergency.

Volodymyr Mushchanov, Аnna Zubenko, Maxim Tcepliaev
Features of Implementation of Numerical Methods of Wind Pressure Research in Modern Software Packages
Donbas National Academy of Civil Engineering and Architecture
Abstract. The publication discusses the features of the implementation in modern software packages of numerical methods for the study of wind pressure and the impact of wind load on the example of structures with a circular cylindrical surface, namely vertical cylindrical tanks of large volumes. The procedure for constructing the design scheme of the structure, the necessary initial and boundary conditions are described. It has been given the recommendations for assigning the dimensions of the computational domain of an isolated structure and as part of a group. The influence of the size and shape of mesh elements on the computation process is noted. The requirements of Eurocode and the norms of the Russian Federation for determining the profile of the wind flow velocity are given. An algorithm for specifying the design scheme and setting the parameters of the SolidWorks Flow Simulation software package for carrying out aerodynamic calculations is considered. The graphs of the distribution of aerodynamic coefficients for vertical cylindrical tanks along the height of the tank are presented.
Keywords: reservoir, three-dimensional computational domain, cylindrical shell, wind, aerodynamic coefficients.