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Item Analysis of Feasibility for Implementing European Standard Railway Tracks in Ukraine(Kaunas University of Technology, Kaunas, Lithuania, 2023) Kurhan, Mykola; Kurhan, Dmytro; Hmelevska, NelyaShow more ENG: The contemporary challenge at hand pertains to the development of theoretical, methodological frameworks, and practical guidelines for establishing railway mainlines in Ukraine aligned with European standards. The objective of this research involves scrutinizing diverse scenarios and, based on this analysis, evaluating the prospects of constructing European standard railway tracks within Ukraine. The introduction of a 1435 mm gauge railway network on a new route within Ukraine necessitates substantial investments in transport infrastructure construction and procurement of rolling stock. An unbiased assessment and definitive determination of prospective directions demand an examination of key criteria characterizing rail-oriented agglomeration tendencies and the volume of transit transportation for both passengers and freight. Additionally, the analysis takes into account the techno-economic potential of these directions.Show more Item The Centrifugal Modeling of Reinforcement on Approaches to Railway Bridges(Óbuda University, Budapest, Hungary, 2022) Alkhdour, Ahmad M.; Tiutkin, Oleksii L.; Marochka, Vitalii V.; Boboshko, Stepan H.Show more ENG: The purpose of the research is to test models of sections with transient stiffness on approaches to railway bridges in the laboratory. The feasibility of the proposed methods of reinforcing the transient stiffness areas to ensure normal operation and avoid the formation of significant deformations had been tested. Centrifugal simulation of three types of reinforcement of transition section had been performed. The deformations of the models of the section with transient stiffness on approach to the railway bridge had been obtained. A comparative analysis of the results of centrifugal experiments had been performed. The effectiveness of each of the reinforcement options had been determined and the most rational method of reinforcement had been concluded.Show more Item Changing the Stress State of the Track Superstructure while Strengthening the Subgrade(VŠB – Technical University of Ostrava, 2020) Tiutkin, Oleksii L.; Neduzha, Larysa O.; Kalivoda, JanShow more ENG: Strengthening the subgrade with the help of various technologies significantly affects the stress state of the track superstructure. The strengthening of the subgrade with piles, leads to an abrupt stiffening of the track superstructure, which is problematic for its normal operation. Two finite element models were created to determine the change in the stress state of the track superstructure when strengthening the subgrade. They fully reflect the geometric, deformation and power characteristics of a real subgrade, which is strengthened by piles. Individual finite elements of the models are provided with the deformation characteristics of the steel rails, reinforced concrete sleepers, soil subgrade, ballast and soil-cement material of piles. The authors carried out the calculation of stress state of the track superstructure for two finite element models. Results are obtained and analyzed to help in choosing the most effective option for strengthening the subgrade.Show more Item Comparative Analysis of Options for Strengthening the Railway Subgrade with Vertical Elements(Printing House “Technologija”, Kaunas, Lithuania, 2021) Tiutkin, Oleksii L.; Keršys, Robertas; Neduzha, LarysaShow more ENG: In paper the task set to investigate and determine the impact of the parameters for strengthening with vertical elements (piles) on the stress and displacement of the track superstructure. The scientific hypothesis is the possibility of selecting such parameters of these elements that minimally affect the stress state of the track superstructure. For this finite-element models of two options for strengthening have been developed. Using a professional complex at different values of deformation characteristics values of displacements and stresses were obtained. The analysis of the stress-strain state for both options reveals that the more effective option of strengthening the subgrade. It has a more positive effect on the deformation state of the subgrade, reduces the vertical displacement of the track superstructure, reduces its stress state, the value of which allows us to testify to the normal operation of the subgrade.Show more Item Comparative Analysis of the Results of Calculating the Stability of a Reinforced Subgrade with Geosynthetic Materials(Kaunas University of Technology, 2021) Andrieiev, Volodymyr S.; Tiutkin, Oleksii L.; Hubar, Oleksіy V.; Markul, Ruslan V.Show more ENG: Тhе article presents the results of studies of the stress-strain state of the reinforced and unreinforced railway subgrade. Тhis study compares changes in the distribution of stresses and displacements in а railway subgrade. Comparisons of stresses and displacements made it ossible to obtain: - comparative analysis of the work of the main site of the subgrade under increased load with reinforcement and without reinforcement; - comparative assessment ofthe efficiency ofthe reinforced subgrade at increased load; - isolines and isofields of displacements and stresses in the body ofthe embankment at an increased load.Show more Item The Comparative Analysis of the Stress-Strain State of the Support of the Escalator Tunnel Constructed in Weak Soils by the NATM(IOP Publishing Ltd, 2022) Radkevych, Anatolii V.; Tiutkin, Oleksii L.; Kuprii, Volodymyr; Bielikova, SofiiaShow more ENG: The construction of underground objects of the subway is always associated with building of structures connecting the surface. For subways, such structures are escalator tunnels. During the construction of the Dnipro Metro, these underground structures are built using a new technology that forms a multilayered support. This technology is the New Austrian tunneling method. A special feature of its application under the conditions of the Dnipro city is the existence of weak rocks in the upper part of the escalator tunnel. To ensure their stability, various special operational techniques are used that impact the rock massif. The basic techniques include artificial freezing, which was the dominant strengthening technology, and chemical strengthening (cementation), which is more consistent with the New Austrian tunneling method. To elucidate the effectiveness of the two strengthening techniques, a finiteelement model of the Dnipro Metro escalator tunnel has been built. The numerical calculation of two variants for the strengthening of weak soils yielded results for a comparative analysis of the stress-strain state. The result of the comparative analysis is the conclusion of greater cementation efficiency when strengthening weak soils of the massif in which the escalator tunnel is constructed using New Austrian tunneling method.Show more Item A Comprehensive Procedure for Estimating the Stressedstrained State of a Reinforced Concrete Bridge Under the Action of Variable Environmental Temperatures(РС ТЕСHNOLOGY СЕNTЕR, Kharkiv, Ukraine, 2021) Kovalchuk, Vitalii V.; Onyshchenko, Artur; Fedorenko, Olexander; Habrel, Mykola; Parneta, Bogdan Z.; Voznyak, Oleh M.; Markul, Ruslan V.; Parneta, Mariana; Rybak, RomanShow more ENG: This paper reports the full-scale experimental measurements of temperature distribution over the surfaces of bridges’ steel-concrete beams under the influence of positive and negative ambient temperatures. It has been established that the temperature is distributed unevenly along the vertical direction of a bridge’s steel-concrete beam. It was found that the metal beam accepted higher temperature values. The maximum registered temperature difference between a metal beam and a reinforced concrete slab at positive ambient temperatures was +9.0 °C, and the minimum temperature difference was −2.1 °C. The mathematical models for calculating a temperature field and a thermally strained state of bridges’ steel-concrete beams under the influence of variable climatic temperature changes in the environment have been improved, taking into consideration the uneven temperature distribution across a bridge’s reinforced concrete beam. The possibility has been established to consider a one-dimensional problem or to apply the three-dimensional estimated problem schemes as the estimation schemes for determining the thermoelastic state of reinforced concrete bridges. The temperature field and the stressed state of bridges’ reinforced concrete beams were determined. It was found that the maximum stresses arise at the place where a metal beam meets a reinforced concrete slab. These stresses amount to 73.4 MPa at positive ambient temperatures, and 69.3 MPa at negative ambient temperatures. The amount of stresses is up to 35 % of the permissible stress values. The overall stressed-strained state of a bridge’s reinforced concrete beams should be assessed at the joint action of temperature-in- duced climatic influences and loads from moving vehicles.Show more Item Controlling the Dynamic Characteristics of Steel Bunker Containers for Bulk Materials(IOP Conference Series: Earth and Environmental Science, 2024) Bannikov, Dmytro O.; Tiutkin, Oleksii L.; Hezentsvei, Yukhym; Muntian, Antonina O.Show more ENG: The article presents the main results of research devoted to the definition and analysis of the dynamic characteristics of steel small-sized bunker containers for storing bulk materials. All studies were carried out using the finite element method with the use computer complex SCAD. The object of research was a bunker of a bypass track for feeding bulk materials with a total volume of up to 70 m3. The study analysed the natural partial frequency spectrum and the partial oscillation modes of individual load-bearing elements of the bunker. Based on the results of the data analysis, a rather high quantitative density of the natural frequency spectrum was determined. At the same time, its lower limit is about 25-30 Hz for an empty bunker capacity and decreases to 3-5 Hz when the bunker is fully loaded, which is dangerous from the point of view of the possibility of resonance phenomena. In order to qualitatively and quantitatively control the dynamic characteristics, it was proposed to change the steel strength of the structure, which made it possible to change the natural frequencies by about 15% for every 100 MPa change in steel strength for the bunker containers of the considered type.Show more Item Determination of the Type and the Length for the Transition Curves on the Directions of High-Speed Train Operation(Széchenyi István University, Győr, Hungary, 2022) Kurhan, Mykola ; Kurhan, Dmytro ; Husak, Marina ; Hmelevska, NelyaShow more ENG: In many countries around the world, a cubic parabola is used as transition curves in a simplified form. Today, the properties of many mathematical curves are well studied, which can be used as transition curves. The object of research is the process of restructuring transition curves when organizing high-speed trains operation. The use of modern means of mathematical modelling allows to add a number of dynamic characteristics for evaluation parameters of motion in the curved sections of the tracks. Thus, with an increase in speed for transition curves, both the values of unbalanced acceleration and its change in time, and also the velocity attenuation of oscillations of rolling stock when moving from a transition curve to a circular curve or to a direct section. On the basis of the conducted research, it has been found that when increasing the speed of the vehicle movement in the range from 120 to 200 km/h, the length of the stabilization section increases at the output of the curvature by an average of 20 m for every 40 km/h. The analysis showed that with correctly set parameters of transition curves, which correspond to the maximum speed of movement and radius of a circular curve, the strength and reliability of the bearing elements in the structure of the permanent way and the travel comfort are fully ensured.Show more Item Determining Features of the Deformed State of Reinforced Concrete Beams of Road Bridges When Strengthening the Span Structures(РС Тесhnology Сеntеr, Kharkiv, Ukraine, 2022) Kliuchnyk, Serhii; Spivak, D.; Goryushkin, I.Show more ENG: The technology of repairing reinforced concrete bridges typically involves closing traffic on one half of the structure and performing work on it when it is possible to move vehicles on the second part of this structure. The main process of interest to practitioners in terms of hardening concrete, which occurs in the beams of a span structure during the passage of a temporary moving load, is deformation. By the time the cement of freshly laid concrete of the overhead reinforcement slab is hardened, it is necessary to create the necessary conditions for this (temperature, humidity, immobility over time, etc.). Before concrete acquires strength, movements arising in the span structure cause the destruction of cement stone at the formation stage. It is necessary to investigate the presence of deformations, as well as their impact on the impossibility of forming a homogeneous structure of concrete and its adhesion to reinforcing elements that combine the existing slab with the new one. This study has established deformations induced by a temporary load from 1.61 to 5.83 mm, which have a negative impact on the process of solidification of concrete in the reinforcement slab for a span structure during the repair of a motorway bridge. The three-dimensional models were calculated by simulating a bridge of the M-04 highway. The results underlie the conclusions that the technology of repair work does not take into consideration the required conditions for high-quality concrete strength acquisition in an additional slab. The study results established that operations on concreting an additional overhead reinforcement slab in the presence of vibrational effects exerted by the temporary load on the span structure cannot be performed because of the destruction of concrete at the hardening stage. Given the above issue, several ways to address it have been devised and analyzed; the best of them is recommended.Show more Item Determining the Deformation Characteristics of Railway Ballast by Mathematical Modeling of Elastic Wave Propagation(MDPI, 2023) Kurhan, Dmytro ; Kurhan, Mykola ; Horváth, Balázs; Fischer, SzabolcsShow more ENG: The article solves the problem of theoretically determining the deformable characteristics of railway ballast, considering its condition through mathematical modeling. Different tasks require mathematical models with different levels of detail of certain elements. After a certain limit, excessive detailing only worsens the quality of the model. Therefore, for many problems of the interaction between the track and the rolling stock, it is sufficient to describe the ballast as a homogeneous isotropic layer with a vertical elastic deformation. The elastic deformation of the ballast is formed by the deviation of individual elements; the ballast may have pollutants, the ballast may have places with different levels of compaction, etc. To be able to determine the general characteristics of the layer, a dynamic model of the stress–strain state of the system based on the dynamic problem of the theory of elasticity is applied. The reaction of the ballast to the dynamic load is modeled through the passage of elastic deformation waves. The given results can be applied in the models of the railway track in the other direction as initial data regarding the ballast layer.Show more Item Determining the Strained State of Prefabricated Metal Corrugated Structures of a Tunnel Overpass Exposed to the Dynamic Loading from Railroad Rolling Stock(РС Тесhnology Сеntеr, Kharkiv, Ukraine, 2022) Kovalchuk, Vitalii V.; Koval, Maksym; Onyshchenko, Artur; Kravets, Ivan B.; Bal, Olena M.; Markul, Ruslan V.; Vikhot, S.; Petrenko, Oleksiy V.; Rybak, Roman; Milyanych, Andriy R.Show more ENG: This paper reports the analysis of prospects for the use of prefabricated metal corrugated structures in the body of the embankment of a railroad track in the form of a tunnel overpass in order to pass road vehicles and railroad rolling stock. A technique of inertial dynamic tests of the deformed state of a tunnel overpass from prefabricated metal corrugated structures during the passage of railroad rolling stock is given, by measuring accelerations at the top and on the sides of overpass structures. An algorithm is proposed for processing the acceleration signal for assessing the strained state of metal corrugated structures of a tunnel overpass under the action of dynamic load from railroad transport. Experimental dynamic measurements of accelerations arising at the top and on the sides of a tunnel overpass during the passage of passenger and freight railroad rolling stock were carried out. The maximum value of accelerations arising at the top of a tunnel overpass during the passage of a freight train was 7.99 m/s2, and when passing a passenger train – 6.21 m/s2; the maximum accelerations that occur on the sides were 2.63 m/s2 and 1.77 m/s2. It is established that the maximum deformations of metal corrugated structures of the top of a tunnel overpass, when passing freight and passenger trains are, respectively, 1.63 mm and 1.11 mm. The maximum strains of metal corrugated structures on the sides of an overpass are 1.07 mm and 0.48 mm. The value of relative deformations in the vertical and horizontal dimensions of the structures of a tunnel overpass under the action of dynamic loads from the railroad rolling stock has been found. The relative vertical strains of an overpass amounted to 0.020 %; horizontal – 0.012 %. The practical significance of this work is that with the help of the devised procedure for measuring accelerations, it is possible to assess the strained state of metal corrugated structures under the influence of dynamic loads from the railroad rolling stock.Show more Item Development of High-Speed Railway Network in Europe: A Case Study of Ukraine(Budapest University of Technology and Economics, Budapest, Hungary, 2024) Kurhan, Mykola; Fischer, Szabolcs; Tiutkin, Oleksii; Kurhan, Dmytro; Hmelevska, NelyaShow more ENG: The current task today is the development of theoretical and methodological approaches, as well as practical recommendations for determining the technical feasibility of creating high-speed railway (HSR) lines in the European context. The development of railways in individual countries, followed by the creation of a pan-European high-speed railway network, has raised questions about the compatibility of the technical systems of individual national HSRs. This paper addresses these issues using the example of Ukraine. The research is based on an analysis of scientific developments related to the design of HSR lines and the synthesis of European experience in identifying priority route directions in Ukraine. For comparing various scenarios for the development of railway connections, the authors have developed a forecasting and efficiency assessment model based on the Net Present Value (NPV) indicator. It has been demonstrated that considering the population attracted to HSR and the volume of transit passenger transportation alone is insufficient to achieve the normative investment payback. This situation can only be rectified by implementing mixed traffic involving high-speed passenger trains and accelerated freight trains. However, mixed traffic of passenger and freight trains on high-speed rail lines may face numerous issues and constraints that require careful planning and coordination.Show more Item Development of Methods to Increase the Efficiency of Railway Maintenance(ScientificRoute OÜ publisher, Tallinn, Estonia, 2022) Patlasov, Oleksandr M.; Fedorenko, Yelyzaveta; Shulha, DenysShow more ENG:Object of research: technology of track maintenance optimization. Solved problem: In the development of decisions to optimize the decision-making system in the content of the upper structure of the track used methods of control theory, systems analysis, methodology of optimal control. Main scientific results: An analysis of the degrees of research on improving the efficiency of the technical management of railways showed that there was no systematic approach and that existing developments in the organization, in particular the relative optimization, Separate track repair standards or take into account parameter models, process requirements and conditions. Area of practical use of research results: industrial enterprises, railway stations. Providing the stable support of the railway, sustainable and rhythmic operation of railway traffic is ensured. About 7.3 thousand km are exploited in the ferrous metallurgy of Ukraine. More than 70 % of routes are up to 500 km long and belong to a large company. Consequently, an important task is to maintain the technical state of railways at the production demands level. Innovative technological product: combined transportations that can interact with similar networks of foreign countries. Scope of application of innovative technological product: formation and effective functioning of railway-transport complex, improvement of tariff policy, substantiation of perspective parameters of transportation process and its technical means, creation of advanced technologies, choice of rational structure of transport network, formation of transport corridors, development of fundamentally new management systems.Show more Item Development of the High-Speed Running of Trains in Ukraine for Integration with the International Railway Network(Óbuda University, Budapest, Hungary, 2022) Kurhan, Dmytro ; Kurhan, Mykola ; Hmelevska, NelyaShow more ENG: Most European countries successfully solve the problem of national passenger transportation due to a significant increase in speed. Such measures are carried out both on existing railways through their modernization, and on specially built lines. Mass passenger transportation along the HSN has confirmed their extremely high reliability, safety, economic efficiency, ecological cleanness, and attractiveness for passengers. The creation of international networks based on the potentials of individual countries leads to the need for establishing the following operational and technical parameters of domestic high-speed railway lines, which would have operational compatibility with the Trans-European HSN. The interconnection between the volume of passenger traffic with the specified factors allows to predict promising passenger flow and evaluate the effectiveness in the organization of high-speed running in a particular direction. The economic integration of countries in the European Union allows increasing passenger flows on international travel. This circumstance leads to the problem solution in connecting national high-speed highways into a single European network.Show more Item Effective Jet-Grouting Application for Improving the State of Deformation of Landmarks(MDPI, 2022) Severino, Alessandro; Wahrhaftig, Alexandre de Macêdo; Tiutkin, Oleksii L.; Gubashova, Valentyna; Neduzha, LarysaShow more ENG: The problem of improving the state of deformation of landmarks is an important aspect when performing civil services, because they have a historical interest and bring symbolisms which relate to an event of particular interest for the community. The engineering–geological surveys, technical evaluation and operational suitability of landmarks of national significance are performed to improve the state of deformation. The conducted analytical assessment of landslide hazard slope stability in the RocScience Slide computational complex shows that in the presence of landslide prevention works, and the stability coefficient is increased by a factor of 1.21–1.37. The regularities of deformation and strength parameters of the soil–cement obtained during the jet-grouting application indicated an increase in strength gain of amplifier elements by an average of 1.6–4.0 times. This proves the effectiveness of the jet-grouting application for improving the state of deformation of landmarks of national significance.Show more Item Entropy Application for Simulation the Ballast State as a Railway Element(Óbuda University, Budapest, Hungary, 2023) Kurhan, DmytroShow more ENG: The purpose of the paper is to develop methods of entropy application for simulation of the ballast layer operation of a railway track in the tasks of predicting and controlling the service life. The author developed a method for determining the entropy of the ballast layer as an element of a railway track through calculations of the mechanical work performed by ballast as a result of the reaction to an external load. To determine the array of stresses and deformations operating in the ballast layer space, the spatial model of the stress-strained state of a railway track based was used on the elastodynamic problem. The major part of the developed method is supplemented by the technique of assessing the entropy of a system according to the deviation measuring results in its geometric position. The geometric position of a railway track was measured by a track renewal train. Files archiving to determine the randomness of data recorded in them were carried out using the LZMA algorithm. The tasks of predicting and controlling the service life of ballast have been further developed. The usage of entropy has allowed simulating the ballast degradation as a random process that depends on cyclic stresses and deformations arising in ballast from rolling stock. For the first time, the method of assessing the quality of the track surfacing through the entropy of the ballast layer is proposed. The developed mathematical tool may be used to compare the service life of ballast in various operating conditions, which allows optimizing consistency between the track design and parameters of train movements.Show more Item Examination of Concrete Canvas under Quasi-Realistic Loading by Computed Tomography(MDPI, 2023) Balázs, Eller; Movahedi, Rad M.; Fekete, Imre; Szalai, Szabolcs; Harrach, Dániel; Baranyai, Gusztáv; Kurhan, Dmytro ; Sysyn, Mykola; Fischer, SzabolcsShow more ENG: The current paper concerns the investigation of CC (Concrete Canvas), a unique building material from the GCCM (geosynthetic cementitious composite mat) product group. The material is suitable for trench lining, trench paving, or even military construction activities, while the authors’ purpose is to investigate the application of the material to road and railway substructure improvement. This research was carried out to verify the material’s suitability for transport infrastructure and its beneficial effects. The authors’ previous study reported that the primary measurements were puncture, compression, and the parameters evaluated in four-point bending (laboratory) tests. However, based on the results, finite element modeling was not feasible because the testing of the composite material in a single layer did not provide an accurate indication. For this reason, the material characteristics required for modeling were investigated. A unique, novel testing procedure and assembly were performed, wherein the material was loaded under quasi-realistic conditions with a crushed stone ballast sample and other continuous particle size distribution samples in a closed polyethylene tube. In addition, the deformation of the material following deformed bonding was measured by computed tomography scanning, and the results were evaluated.Show more Item Finite-Element Analysis of Strengthening the Subgrade on the Basis of Boring and Mixing Technology(The Silesian University of Technology, 2021) Tiutkin, Oleksii L.; Neduzha, Larysa O.; Kalivoda, JanShow more ENG: One of the effective techniques to strengthen the subgrade is boring and mixing technology, which is based on the immersion of vertical elements – piles into the subgrade. This method of strengthening significantly affects the stress state of the track superstructure. Two options of the placement of strengthening elements are examined in this paper. To determine the influence of position of strengthening elements on the stress state of the track superstructure, appropriate finite-element models were created. The models fully reflect the geometric and deformation characteristics of a real subgrade, which is strengthened by piles. The calculated stress state of the track superstructure is shown and analyzed in this paper. The main contribution of the paper lies in optimization of the geometric parameters of the technology to reduce the stress state of the "track superstructure–subgrade–soil basement" system. The results show that the location of piles near the rails is more effective than the location of piles near the ballast section.Show more Item Increasing the Efficiency of the Railway Operation in the Specialization of Directions for Freight and Passenger Transportation(Obuda University, Hungary, 2022) Kurhan, Mykola ; Kurhan, Dmytro ; Husak, Marina ; Hmelevska, NelyaShow more ENG: It is shown that in the mixed traffic of trains compared to the directions specialized for transportation of freight and passengers, the traffic capacity is sharply reduced, and costs on repairs and maintenance of track infrastructure increase by 1.5-2 times. The paper outlines ways to solve the problem in the distribution of directions with mainly freight and passenger traffic to increase the traffic capacity of transportation on the rail network. Among the activities, there is the transmission of transit freight flow on parallel runs. Furthermore, changing the operation conditions of railways in the case of implementing the high-speed trains traffic requires strengthening the existing railway lines in the event of insufficient reserves.Show more