Browsing by Author "Markul, Ruslan V."

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Comparative Analysis of Calculation Results of Supporting Structure of Soil-Cement Piles
(Kaunas University of Technology, Kaunas, 2019) Pshinko, Oleksandr M.; Petrenko, Volodymyr D.; Tiutkin, Oleksii L.; Andrieiev, Volodymyr S.; Hubar, Oleksіy V.; Ihnatenko, Dmytro Yu.; Markul, Ruslan V.
ENG: Abstract. The article presents the results of comparison of the stress-strain state of 4 models of a retaining wall structure of soil-cement piles on a landslide-prone slope. This study compares the changes in the stress distribution and displacements in the model elements of the retaining structure of soil-cement piles depending on the design parameters and the method of piles location in the body of the soil mass. The comparison of models of supporting structures of soil-cement piles on a landslide-prone slope allowed obtaining: –the comparative analysis of the quality work of individual elements of the supporting structure for strength and deformation in a three-dimensional representation; –the comparative assessment of the performance of the supporting structure of soil-cement piles on a landslide-prone slope; – histograms of dependences of changes in the angle of piles inclination to the vertical axis of their holding force, strength and deformation of the slope;
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.
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.
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, Roman
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.
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.
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.
Development of Devices for Long-Term Railway Track Condition Monitoring: Review of Sensor Varieties
(Óbuda University. Budapest, Hungary, 2025) Kurhan, Dmytro; Kovalchuk, Vitalii V.; Markul, Ruslan V.; Kovalskyi, Denis
ENG: There are numerous methods for monitoring the condition of railway tracks. In most cases, either the geometry of the railway track or its interaction parameters with moving trains are checked. This work is a component of a project aimed at developing a methodology for installing sensors (sensor networks) for continuous (long-term) monitoring of railway track condition. Therefore, its main objective is to analyse and discuss interim results regarding the feasibility of applying various types of sensors installed on railway track elements. The authors considered three options for sensor application for the overall assessment of railway track condition: measuring stresses in rails with strain gauges, measuring accelerations of rail and sleeper vibrations with accelerometers, and measuring the speed of wave propagation in ballast. Each method has its own advantages and disadvantages. Considering the analysis conducted, each method, both independently and in combination with others, can be applicable for building systems for long-term monitoring of railway track condition. Such systems can be useful, both for solving practical track maintenance tasks during operation and for scientific research.
Features of the Nonlinear Calculation of the Stress-Strain State of the "Rock Massif–Excavation Support" System Taking into Account Destruction
(Kaunas University of Technology, Kaunas, Lithuania, 2019) Shashenko, Oleksandr; Shapoval, Volodymyr; Khalymendyk, Oleksii; Andrieiev, Volodymyr S.; Arbuzov, Maxim; Hubar, Oleksіy V.; Markul, Ruslan V.
ENG: The algorithm for estimating the reliability of the results of the calculation of the stress-strain state of the “rock massif-excavation support” system, taking into account the non-linear relationship between stresses and strains, as well as the destruction of the rock, is presented. In the course of a numerical experiment, it was shown that to determine the reliability of the calculation results, it is enough to find the relative error between the maximum efforts in the lining and then the extremum (more precisely, the maximum) of the “relative error – depth of the excavation center”.
Investigation of the Operation of the Railway Track with Reinforced Concrete Sleepers in Curved Sections with Radius R ≤ 350 m
(Printing House “Technologija”, Kaunas, Lithuania, 2020) Markul, Ruslan V.; Hubar, Oleksіy V.; Arbuzov, Maxim; Andrieiev, Volodymyr S.; Tiutkin, Oleksii L.; Savyts’kyy, V.; Ganich, Ruslan Ph.
ENG: The article presents the results of the research on polygon extension for laying reinforced concrete sleepers under difficult conditions (R≤350 m, mountainous terrain) with ensuring safety traffic and reliable operation of the railway track. Changes in the geometry of the track in the plane with wooden sleepers and Д0 fastener as well as reinforced concrete sleepers with СКД65-Б fastener in the curve with the radius of 350 m were investigated. The results of the research allowed to obtain: - method and algorithm for determining the tapping section of the track gauge extension on reinforced concrete sleepers in curves with radius R ≤ 350 m; - comparative assessment of the track gauge change with the use of Д0 fastener (wooden sleepers) and СКД65-Б fastener (reinforced concrete sleepers) in curves with a radius R ≤ 350 m; - factors impact on the track gauge extension under difficult operating conditions; - empirical dependence of the process of the track gauge width change and the frequency of its adjustment in the cases of СКД65-Б fastener (reinforced concrete sleepers) and Д0 fastener (wooden sleepers) use in curves with radius R ≤ 350 m; - conclusions on the probability and feasibility of concrete sleepers use under mountainous terrain conditions, including difficult operating conditions (R ≤ 350 m).
Mathematical Modeling of Filtration and Geomigration Under Conditions of Anthropogenic Load
(Український державний університет науки і технологій, Дніпро, 2025) Bubnova, Olena A.; Miroshnik, Vitaliy A.; Markul, Ruslan V.; Mashykhina, Polina B.; Tatarko, Larysa H.
ENG: Purpose. The aim of this study is to develop mathematical models for predicting the processes of contamination of the aeration zone and groundwater in the event of leachate leakage from a solid waste landfill. The mathematical models take into account typical hydrological parameters: porosity of the aeration zone, aquifer, filtration coefficient of the aeration zone, filtration coefficient of the underground aquifer, intensity of leachate infiltration into the aeration zone and underground aquifer. Methodology. A one-dimensional filtration equation and a one-dimensional mass transfer equation were used to model the process of infiltrate migration in the aeration zone. The modeling of the process of contamination of the underground aquifer, which receives infiltrate from the landfill, was carried out on the basis of a two-dimensional equation (planned model) of geomigration. For the numerical integration of the model equations, a variable-triangular finite-difference splitting scheme was used. The numerical integration of the two-dimensional geomigration equation is performed using the splitting scheme. The peculiarity of the proposed numerical models is that the value of the unknown function can be determined by an explicit formula. Findings. Numerical models have been developed to solve the complex problem of predicting the contamination of the aeration zone and underground flow in the case of infiltration of an impurity from a solid waste landfill. Originality. Numerical models of filtration and mass transfer of impurities in the case of migration of infiltrate from a municipal solid waste landfill through the aeration zone and into groundwater are proposed. To apply these mathematical models, standard hydrological information is required. The models are aimed at solving complex problems in the field of environmental safety and protection. They make it possible to determine the negative impact of landfills on the environment at the stage of justifying the location of future landfills and their size. Practical value. The proposed mathematical models use standard hydrological information, which is important for serial calculations in design organizations, and can be useful for assessing the impact of landfills on environmental pollution.
Methods of Assessment of Ballast Contamination on Railways of Ukraine
(Technologija, Kaunas, 2022) Andrieiev, Volodymyr S.; Tiutkin, Oleksii L.; Hubar, Oleksіy V.; Markul, Ruslan V.; Mukhina, Nataliya
ENG: Ukrainian railways use a wide variety of methods for determining ballast contamination. Some regional branches of JSC "Ukrzaliznytsia" prefer to replace the old ballast with new instead of cleaning it. Others do the cleaning of crushed stone ballast. The periodicity of such crushed stone cleaning depends on local conditions and features of cargo transportation. Ballast contamination assessment plays an important role in this matter. The essence of the research is to reduce the time for obtaining results on the assessment of ballast contamination and to simplify it for use by one or two persons, who can act as track installers.
Modeling the Dynamics of Groundwater in Applied Problems
(ESI “Prydniprovska State Academy of Civil Engineering and Architecture”, USUST, Dnipro, 2025) Tiutkin, Oleksii L.; Bubnova, Olena A.; Markul, Ruslan V.; Miroshnyk, Vitalii A.; Mashykhina, Polina B.
ENG: Problem statement. Forecasting and analyzing groundwater dynamics under anthropogenic impact on aquifers is a pressing issue. This task arises when designing drainage systems for flooded areas, designing water intakes from underground sources, the impact of waste disposal sites on the movement of groundwater, and water leakage from water supply and sewage systems. Anthropogenic impact can affect both groundwater (unconfined aquifers) and confined aquifers. Technogenic impact can occur through a system of wells, leakage of effluents from landfills, infiltration of precipitation, and irrational irrigation. Solving this type of problem requires the use of multifactorial filtration models. The purpose of the article. To conduct a comprehensive analysis of mathematical models in groundwater dynamics problems and to identify their advantages and disadvantages. Conclusions. The analysis showed that the modern approach to solving groundwater dynamics problems is to use multidimensional filtration equations that take into account changes in the groundwater level (or hydrodynamic pressure in the confined aquifer) over time. These modeling equations take into account water infiltration into underground horizons. The boundary conditions of the modeling filtration equations that ensure the correct formulation of the boundary problem are considered. It is shown that the formulation of specific groundwater dynamics problems (drainage, operation of water intake wells, etc.) is implemented in models by setting “internal” boundary conditions. Applied problems are analyzed where models of unconfined and confined groundwater flow can be used.
On the Question of Choosing the Optimal Strength Criterion of Soils and Rocks
(Kaunas University of Technology, Kaunas, 2021) Shashenko, Oleksandr; Shapoval, Volodymyr S.; Skobenko, O.; Zhylinska, S.; Andrieiev, Volodymyr S.; Markul, Ruslan V.; Mukhina, Nataliya
ENG: Based on the analysis of solutions to the classical problems of soil mechanics and geomechanics on determining the critical height and angle of the slope, as well as active and passive pressure on the enclosing structures, to identify the optimal strength criteria and the limits of their application, which allow predicting the destruction of ideally free-flowing, ideally plastic rocks, as well as rocks characterized by internal friction and specific cohesion, which is necessary for calculating the strength and stability of underground and open mine workings in the supercritical region - after the destruction of the near-contour region. The areas of application of some criteria for the strength of soils and rocks are outlined and substantiated. It is shown that, in contrast to the known strength criteria of Z.T. Benyavsky, Hoek - Brown and A.N. Shashenko Coulomb - Mohr strength criterion and our proposed modification of the strength criterion of A.N. Shashenko allow predicting the destruction of ideally - free flowing, ideally - plastic rocks, as well as rocks characterized by internal friction and specific cohesion.
Study of the Interaction of the Railway Track and the Rolling Stock Under Conditions of Accelerated Movement
(IOP Publishing, 2020) Hubar, Oleksіy V.; Markul, Ruslan V.; Tiutkin, Oleksii L.; Andrieiev, Volodymyr S.; Arbuzov, Maxim; Kovalchuk, O.
ENG: Comprehensive studies of the interaction of the railway track and the investigated rolling stock under accelerated conditions have been carried out. The basis of the research was to obtain and substantiate the process of stress state, force interaction of the railway track and the rolling stock under conditions of accelerated movement. Introduction of the new rolling stock into continuous operation is a serious task that must be solved comprehensively. The implementation of this direction significantly affects the reliability of the elements of the railway track. Within the framework of the research, the approach was used that takes into account theoretical and experimental parts of the research using the methodology of prof. O. P. Yershkov. As a result of the studies, average stress values were established: in rails, they variate within the range 44.37...70.99 MPa; in the sleeper, they reach 0.78 MPa; in the ballast layer, they have 0.13 MPa; in the body of the subgrade, they reach 0.04 MPa, which is significantly less than the maxima allowable values. While speed change from 140 to 160 km/h, the values of the studied parameters decrease: vertical force (9.39 %), lateral forces (19.79 %); stresses in the edge of the rail flange (15.86 %); stresses in the edge of the rail head (16.67 %); stresses in the neck of the rail (8.74 %). The obtained results made it possible to form trends and recommendations on the feasibility of further increasing speeds development. At the same time, this made it possible to substantiate in more detail the operation of the railway track in the case of accelerated movement.