Vadim Gubanov, Elena Olenich
Wear Peculiarity of Steel Chimneys with Guys
Donbas National Academy of Civil Engineering and Architecture
Abstract. This article discusses the methodology of conducting full-scale studies of steel chimneys with guys, based on the experience of surveys of building structures. This technique is based on the structuring of load-bearing and additional structures, which must be taken into account when examining, zoning structures according to the degree of wear and planning maintenance. The article also provides a classification of the limiting states of structures, considers the criteria for the failure of structures, identifies the categories of responsibility of individual elements. The most common types of defects and damages of steel chimneys are presented, quantitative characteristics of these types are determined. The most significant defects and damages affecting the bearing capacity of the structure include general and local corrosion wear, roll of the pipe trunk, breakage and weakening of the tension of the guy ropes.
Keywords: defect, damage, chimneys, guys, corrosion wear; reinforcement of structures, maintenance.
Vladimir Anishсhenkov, Andrey Mironov
Application of Pipe Concrete Structures in Construction
Donbas National Academy of Civil Engineering and Architecture
Abstract. The article examines the analysis of the use of pipe concrete structures in bridge construction and construction of high-rise buildings in Russia, Ukraine, USA, Japan, Australia, China and other countries. The advantages and disadvantages of pipe concrete structures are indicated, some types of load-bearing structures in the form of pipe concrete columns with various reinforcement of concrete inside the pipe are presented: with an unreinforced pipe-concrete core; a pipe-concrete core reinforced with high-strength reinforcement; a rigid frame assembly; the coupling of the column with the overlap. Some types of junctions of a pipe-concrete column with crossbars are considered, as well as pipe-concrete column structures in which there is no coupling of the concrete core with a steel shell pipe, which creates additional advantages in reducing the cost of construction of multi-storey high-rise buildings. The article mentions a number of Russian scientists who were engaged in research of pipe concrete structures and made a significant contribution to the development of calculation, design and construction of facilities using these structures. As a result of the analysis of literary sources with the subsequent identification of problems in the design of pipe concrete structures, the relevance of the study of junctions of pipe concrete columns with crossbars in high-rise multi-storey construction was determined.
Keywords: bridge construction, multi-storey building, pipe concrete element, concrete core, steel mantle pipe, strength of pipe concrete, column, crossbar, rigid frame assembly, transverse deformations, stress-strain state.
Anton Tanasoglo, Serafim Fomenko, Sergii Bakayev, Lyudmila Kozlova
Determination of Reduced Tension at Conductive Wires and Lightning Protection Cables Breakage of Overhead Power Lines with a Voltage of 35–110 kV
Donbas National Academy of Civil Engineering and Architecture
Abstract. The article aims to develop a numerical-analytical method of solving the problem about determining the tension of wire after its breakage. Solution of this problem is realized in software package MS «Excel». As the model was taken the part of overhead power transmission line (OPTL) – anchored site, consisting of two anchor supports and intermediate supports located between them, to which are suspended conductive wires and lightning protection cable. Supports are considered as the components of all constructional system of the power grid. Wire breakage is modeled serially in each of eleven spans. At calculation the value of the reduced tension of wire calculated to know the load on an intermediate support in crash conditions and magnitude of sag wire in the span adjacent to the emergency span is analyzed. The attention to flexibility of supports of OPTL is paid. It is established that the flexible support deviate towards the survivor wire under the influence of its tension, and support deflection is also added to the displacement of the suspension point due to deviation the insulator string. Based on the calculation and generalization of the results dependence of the value of reduced tension from the number of follow-up spans of anchor site with the survivor wire is revealed and the number of spans required to find the maximum value of reduced tension is determined.
Keywords: overhead power transmission line, reduced tension, spatial model, overhead power transmission line support, set of equations, design loads.
Yevgen Gorokhov, Natalia Smirnova, Andrey Mironov, Sergii Bakayev
Stress-Strain State of an Anchor Angle Tower 220 kV with Imperfections under the Action of Static Loads
Donbas National Academy of Civil Engineering and Architecture
Abstract. The article analyzes the stress-strain state of the anchor angle tower of an overhead line (OL), which is considered as a spatial repeatedly statically indeterminate through system with hinged nodes. To compare the SSS indicators of the support elements, the schemes were analyzed when working with and without imperfections. In the first scheme, the operation of the structure was considered as “without defects”, in the second scheme, the formation of a general distortion of the lattice elements from the plane of the support face was modeled and the response of the system to elements with imperfections was analyzed. Based on the analysis of the operation of the system with imperfections, it was possible to identify the influence of rods with ultimate deformation on the work both with the elements adjacent to them (barrel, grate) and on the structure as the whole. Based on the results of the research, schemes for tensometric studies of the support U 220-2r+9 were determined.
Keywords: anchor angle tower, overhead power line, stress-strain state, numerical studies, distortion, imperfect structural behavior.