Andrey Mironov, Dmitro Belyy
Stress-Strain State of Framed Pipe-Concrete Assemblies of Bent-Welded Profiles
Donbas National Academy of Civil Engineering and Architecture
Abstract. The article provides an analysis of the work of frame pipe-concrete (TB) units from bent-welded closed profiles (GSP). The selection of the required sections of the GSP and the characteristics of concrete was carried out, taking into account the existing methods for calculating pipe concrete, the current regulatory documents and future experimental studies of real models of TB nodes. A finite element (FE) model of a frame node of a multi-storey frame building was created in the LIRA-SAPR software package using GSP. The finite element method (FEM) was used to numerically calculate the TB of a node in order to identify the patterns of operation of a steel-reinforced concrete frame structure under load. The conclusions on the bearing and deformation capacity of the investigated structure in the place of joining the ledgers (cantilevers) to the TB post have been made. The bearing capacity of the frame TB unit made of GSP according to the first group of limiting conditions is determined.
Keywords: pipe-concrete unit, bent-welded closed profile, finite element method, numerical calculation, load, stress-strain state (SSS), load-bearing capacity.
Sergey Titkov, Anatoly Yugov, Vladimir Vasylev, Eduard Lozinsky
Experimental Study of Wind Impact on the Hyperbolic Cooling Tower in the Wind Tunnel, Taking into Account the Installation Stages
Donbas National Academy of Civil Engineering and Architecture
Abstract. The article presents the results of a comprehensive study of wind impact on a twelve-sided frame-cladding metal cooling tower of hyperbolic shape. Comprehensive experimental research means a series of experimental studies that complement each other and help to build a course of further research, to complete the data or to refute the hypotheses and assumptions of the wind flow around the buildings and structures. The results of weight strain gauge tests to find the total aerodynamic coefficient Cx, Cy, Cmz, the results of conducted drainage experiments to find local coefficients Cpi in the characteristic sections of the tested model and the results of conducted qualitative experiments on visualization of wind impact are given. This work was performed with the purpose of finding the wind impact diagrams on the hyperbolic frame-type metal cooling tower during the installation period from closing to closing of the tier contour to identify the most unfavorable design situations of wind impact.
Keywords: hyperbolic metal cooling tower, hyperbolic shape, strain gauge balance, local coefficient, velocimetry, shadow method.
Vladimir Vasylev, Vladimir Anishchenkov, Mikhail Boyko
Methodology of Experimental Research of Steel Element and Concrete Working Together on the Surface of their Contact
Donbas National Academy of Civil Engineering and Architecture
Abstract. The article presents a methodology for conducting static tests of a concrete prism made of concrete of class B15 to study the adhesion of concrete on a flat surface of a steel element. To conduct experimental studies, an installation consisting of two metal plates with dimensions of 500×100×10 mm was created. Concrete prisms are placed between these plates, which are compressed by a hydraulic press. The concrete sample is installed on a metal square slab with dimensions of 100×100 mm. The load on this structure is transmitted through a circular metal plate with a diameter of Ø200 mm to a metal cylinder with dimensions of 135×50 mm hydraulic jack GD-20, with a load capacity of 20 t. Horizontal deformations of the concrete prism along its length are recorded by an ICH-10 clock type indicator with an entry in the test log. The purpose of the tests was to study longitudinal horizontal shear deformations along the concrete-steel contact, depending on the level of compression of concrete.
Keywords: stress-strain state (VAT), experimental model, pipe-concrete (TB) element, hydraulic press, concrete prisms, chamfer for cylinder, concrete adhesion, steel shell, coefficient of transverse deformation.
Nikolay Pryadko
Reinforcing Brick Walls with Steel Cladding
Donbas National Academy of Civil Engineering and Architecture
Abstract. The article is devoted to the issues of inspection, assessment of the technical condition and development of design solutions for strengthening the walls and foundations of St. John of Kronstadt parish of the Donetsk Diocese of the UOC in the Petrovsky district of Donetsk, Kobrinskaya str., 10, village Trudovskie in order to bring them into working condition. In the work, detailed surveys of the foundations and walls of the building were carried out, a geodetic survey was carried out to assess the magnitude and unevenness of the subsidence of the foundation, geodetic observations were carried out to determine the bulging, slopes and subsidence of the walls. To obtain the strength characteristics of the brickwork, samples of whole bricks of masonry mortar were selected from the wall. In the Testing Center of building products and structures of DNACEA, the brand of brick and the strength of the mortar were determined. The analysis of defects and damages of building structures was carried out. As a result of the analysis of the actual state of the building structures, a set of measures has been developed to restore their integrity and load-bearing capacity. It is proposed to strengthen the foundations with one-sided and two-sided clips. The walls of the building on level +5.320 are proposed to strengthen individual cracks with double-sided metal clips with double-sided clips. Install metal strands around the perimeter of the building and along the axes «2» and «3».
Keywords: temple building, walls, foundations, brick, rubble masonry. defects, damages, deformations, geodetic observations, subsidence, slopes, cracks, reinforcement clips, concrete, steel clips.