Мости та тунелі: теорія, дослідження, практика (ДІІТ)
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ENG: Bridges and tunnels: theory, research, practice
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Browsing Мости та тунелі: теорія, дослідження, практика (ДІІТ) by Author "Boboshko, Stepan H."
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Item Analysis of the Problems of Sections With the Transitional Rigidity Indicator in World Bridging(Дніпровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2019) Marochka, Vitalii V.; Boboshko, Stepan H.EN: Purpose. To analyze the problem of areas with a transitional stiffness on the approaches to the bridges based on the experience of European and American bridge-building. To find out the root causes and methods for detecting track defects in transitional stiffness zones. To propose a pilot model for the development of transitional stiffness areas based on the experience of developed countries in Europe. Methodology. Collection of data on the causes and nature of the occurrence of bumps on approaches to bridges based on the experience of specialists in the design, construction and operation of railway and highway bridges. Analysis of methods of arrangement of transition areas on approaches to bridges in European countries. Results. An analysis of the literary sources of developed countries of the world on the problem of the origin and methods of detection of bumps in areas with transitional stiffness on the approaches of bridges was performed. The results were collected on ways to identify problems in areas with transient stiffness and how to solve them. A model for mathematical and experimental studies was proposed. Origi-nality. Scientific interest is that, despite the extensive experience of developed countries of the world, the Ukrainian norms still do not have a clear mechanism for identifying and characterizing problems of track geometry in sections with transitional stiffness. Thus, studying the experience of more advanced countries in the field helps to con-sider the problem more clearly and standardize its definition. Practical value. If proposed model of reinforcement of transition stiffness areas will be confirmed it allows to reduce the cost of maintaining of the track and to solve the problems of the transitional areas at the stage of bridge construction, that is, before its immediate occurrence.Item Development of Technology of Arranging Areas with Transitional Stiffness Index on Approaches to Railway Bridges(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2018) Marochka, Vitalii V.; Boboshko, Stepan H.EN: Purpose. To investigate the issue of transitional rigidity on the railways of Ukraine, to form a complex of existing measures to strengthen the transitional sections, to develop and justify the solution to the problem of transitional stiffness on approaches to railway bridges. Methodology. Theoretical research methods analysis and synthesis has been used. For mathematical modeling of the structure, a finite element method has been used - a three-dimensional mathematical model was created with stiffnesses corresponding to real ones, and loaded by static load of the rolling stock. Findings. The analysis of the literature and the experience of developed countries on the issue of arranging areas with transitional stiffness index on approaches to railway bridges, proposed and developed a solution for amplifying sections with transitional stiffness, a theoretical calculation of the mathematical model of the corresponding areas was developed the working draft for arranging areas with transitional stiffness index on approaches to railway bridges has been designed. Originality. The technology of amplification of areas with transitional stiffness has been proposed, a model of a section with a transitional stiffness index has been developed and constructed in the first approximation. Practical value. Developed construction of soil-cement piles allows to enhance areas with transitional stiffness index on approaches to railway bridges. The obtained data open up new possibilities in the experimental study of areas with a transitional stiffness index.Item Numerical Analysis of Reinforcement of Sections With Transitional Rigidity on Approaches to Railway Bridges(Dnipro National University of Railway Transport named after Academician V. Lazaryan, Dnipro, 2020) Marochka, Vitalii V.; Boboshko, Stepan H.EN: Purpose. To analyze the mechanism of work of embankments, to model three-dimensional models and to compare methods of their reinforcement on transitional areas on approaches to railway bridges using the Lira software based on finite element method (FEM). To do comprehensive analysis of results and comparison of constructive performance of different reinforcement methods. Methodology. Numerical finite element modeling (FEM) had been performed to study the work of embankments in transition sections on approaches to railway bridges. Four three-dimensional models of the construction of the transitional section, corresponding to the real bridge, had been constructed. These models had been tested for nominal load to evaluate their performance relative to each other. Findings. As a result of the calculations, the deformation characteristics for the basic model and each of the reinforcement types had been obtained, and their comparisons had been made by determining the maximum vertical deformations and vertical deformations at key points. The analyze of feasibility of using the tested reinforcement methods under different real initial conditions had been performed. Originality. The main aspects of the work of the transition sections over long periods of time had been revealed. Comparisons of fundamentally different methods and types of reinforcement of sections with transient stiffness had been made. The expediency of the methods of reinforcement of the embankment construction in the transitional sections that had been proposed in previous works had been tested. Practical value. The proposed reinforcement methods may be used depending on the specific design conditions, the budget, and other factors. Evaluating the work of different types of reinforcement during numerical analysis makes it possible to move away from large-scale field trials and focus on other methods, which significantly reduces time spent on solving current problems.