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Description of rail track geometry deterioration process in Hungarian rail lines No. 1 and No. 140
Abstract
The aim was the perfection of an analytic examination, which describes the track deterioration process, characterized the correspondences more precisely and better to use in practice. This method was based on the destruction's theory of the railway track geometry and it exploited the possibilities of recent computer technology. More than one million measuring car (FMK-004) data were processed than analyzed and defined by configuring and programming a new method. The results of this method were descriptive functions, which afford interpretable information about the geometrically destruction's occurrences of the different railway lines.
... Elimination of speed restriction due to the deterioration of railway track has always been a concern of railway managers. By reducing the train speed, transmission rate of [4,7,28,29]. As mentioned in Table 3, elimination of train speed restriction has a positive effect on prioritization in reconstruction projects. ...
... Speed restriction is generally applied along a certain length of railway blocks to maintain the safety of passing trains. It must be noticed that only sections with speed restriction must be calculated where the speed restrictions are removed after reconstruction [4,7,28,29]. According to this criterion, the railway blocks (alternatives) with more delays due to speed restrictions are in priority for reconstruction, where the costs of the projects are equal. ...
... Analyzing the outputs of the track recording machine (EM120) is one of the methods for measuring track quality which is common in Iran's railway network [33]. It shows the geometric parameters of the track from different aspects such as: twist, alignment, track gauge, and other parameters [28,33,34]. The outputs of the track recording machine, after statistical processing is modified into indexes that are employed in track maintenance. ...
Transportation development is one of the important goals of countries which is associated with economic and social development. Therefore, expanding the transportation infrastructure and construction has always been a key issue for managers in developed and developing countries. Due to the high costs of infrastructure projects in the transportation industry, especially railways as the safest and the most cost-effective mode of transportation, the financial resources must be managed with great sensitivity and precision. In current economic conditions, various methods have been proposed for decision-making in transportation infrastructure projects and prioritization of railway reconstruction projects. In this research, different decision models to prioritize transportation infrastructure projects are reviewed and according to the selected AHP (Analytic Hierarchy Process) model, railway reconstruction projects in Iranian railway networks are prioritized. In this regard, first, reconstruction projects have been reviewed from a technical and economic point of view, and then prioritization has been done according to the weight of effective criteria in the projects. In this study, important criteria for prioritization in terms of importance are considered as: Cost of Reconstruction, Train Speed Restriction, Allowable Speed, Railway Capacity, Traffic, Time, and Railway Track Quality. The effect of cost of reconstruction criterion is about 12 times greater than the time criterion and the output of the model showed that Jalalabad-Golezard block is the first priority for reconstruction in the area of Kerman and Southeastern in Iranian Railways.
... -numerical analysis with finite element method (FEM), static and dynamic approaches [10,12,13,16,25,30,37,38,46,50,53,54,60,69,70], -laboratory tests [2,13,21,22,23,25,26,28,40,52,54,55,56,66,67], -field (in-situ) tests [2,9,10,11,18,24,32,34,35,39,41,52,53,54,55,58,59,61], -image analysis supplemented with Wavelet calculation method, -calculations based on mathematical and physical theories, i.e. MATLAB [17], -mathematical calculation of deterioration and maintenance theories [42,43,44,45,51], -IoT (internet of things) techniques, -electrical measurement methods [14,29], -signal processing for non-destructive testing of railway tracks [59], -mathematical (statistical) regression analysis and artificial intelligence, as well as artificial neural networks [42,43,44,45]. ...
... -numerical analysis with finite element method (FEM), static and dynamic approaches [10,12,13,16,25,30,37,38,46,50,53,54,60,69,70], -laboratory tests [2,13,21,22,23,25,26,28,40,52,54,55,56,66,67], -field (in-situ) tests [2,9,10,11,18,24,32,34,35,39,41,52,53,54,55,58,59,61], -image analysis supplemented with Wavelet calculation method, -calculations based on mathematical and physical theories, i.e. MATLAB [17], -mathematical calculation of deterioration and maintenance theories [42,43,44,45,51], -IoT (internet of things) techniques, -electrical measurement methods [14,29], -signal processing for non-destructive testing of railway tracks [59], -mathematical (statistical) regression analysis and artificial intelligence, as well as artificial neural networks [42,43,44,45]. ...
... There are some interesting results from the international literature review: -significant part of the rail joints' failure is related to reduced moment of inertia of the fishplate pair (compared to parent rail section) [54], as well as increased stress values in the rail head that can lead to plastic deformation, lipping in the rail steel material [25,26,28], -the maintenance cost of rail joints is enormous, it is very significant aspect because the avoiding of insulated rail joints from the CWR tracks is very complicated [54], -it is very important to choose adequate glue material for glued insulated rail joints [2,16,21,22,23,26,60], respectively the endposts' material and thickness [19,21,22,23,26,57,58], -modified railhead geometry (longitudinal section, i.e. arch shape) is able to ensure reduced stresses and higher life-time for rail joints [12,57], -lipping phenomena in the rail head near the endpost can be hindered by higher rail steel grade or modified-treated steel materials in the rail head [26,28,40], -external reinforcement methods are able to ensure higher bending stiffness for fishplated rail joints [54], -the usage of inclined (30° and 45°) rail joints helps with reducing vertical displacement, noise and vibration compared to square ones [11,12,18], -it has to be mentioned that the railway operation practice verified that inclined rail joints are not adequate (i.e. they are not better than square ones) [68], -importance of glue patterns (as well as the quantity of glue material between fishplates and rail web) [52,53,66,67], -the support geometry influences the arising stress-strain state in the rail joint elements [35,37,46,60], -a lot of methods were developed that are adequate for detection faults and stress-strain state in the rail joints (i.e. for example: ultrasonic test, acousto-elastic method, neutron diffraction meth-od, X-ray measurements, usage of optical fibre Bragg grating sensors) [2,7,13,26,41,49,55,56,59,66], -additional dynamic effect due to rail joints can lead to faster deterioration process [9,10,11,24,32,33,34,41,50,51,55,58,60,61,69,70], -the geometrical deterioration process of railway track as well as rail joints can be determined by up-to-date methods, e.g. analysis of measured data of railway track geometry recording cars using with artificial intelligence, artificial neural networks, etc. [42,43,44,45], -unequal elasticity of the subrail base as well as quasi-static calculation method can be considered during railway superstructure calculations [1,36], -dynamic effects of railway vehicles on railway tracks can be measured by railway track geometry recording car (e.g. type Plasser&Theurer EM 250, etc.), values of velocity, accelerations in different directions are able to be measured, derivatives of measures values can be calculated, in this way the occurent geometrical problems of rail joints are able to be determined and localized [3,4,6,62,65]. ...
Purpose. The aim was to compare behavior of polymer-composite fishplated and control steel fishplated (type GTI and MTH-P) glued insulated rail joints in railway track. Methodology. After laboratory tests (shear tests of glue materials, 3-point-bending tests, axial pull tests), as well as field inspections, trial polymer-composite and control (steel) fishplated glued insulated rail joints were built into railway tracks with (almost) the same border conditions (rail profiles, cross section parameters, track condition, etc.). The authors summarize in this paper the results of field tests related to polymer-composite, as well as control (steel) fishplated glued insulat-ed rail joints between 2015 and 2018 considering measured data of track geometry recording car and straight-ness tests. Findings. The investigation and diagnostics of experimental (fiber-glass reinforced fishplate) and control (steel fishplate) rail joints (straightness tests, track geometry recording car measurements) are in pro-gress. Originality. The goal of the research is to investigate the application of this new type of glued insulated rail joint where the fishplates are manufactured at high pressure, regulated temperature, glass-fiber reinforced polymer composite plastic material. The usage of this kind of glued insulated rail joints is able to eliminate the electric fishplate circuit and early fatigue deflection and it can ensure the isolation of rails’ ends from each other by aspect of electric conductivity. Practical value. The polymer-composite fishplated glued-insulated rail joints and control steel fishplated rail joints were built into the No. 1 main railway line (Kelenföld-Hegyeshalom) in Hungary at three different railway stations. The accurate time could not be determined when the polymer-composite fishplated glued-insulated rail joints reach the end of their lifetime as the result of previous research. In this article the investigation of deterioration process of glued-insulated rail joints is demonstrated.
... Most models for analyzing contact problems in all cases of flipping and sliding rely on the classic Hertz solution [1][2][3][4][5][6][7]. In this context where the Hertz solution belongs only to the case with normal force, a generalized model for sliding roller contact problems is presented, taking into account the normal force and the pair of forces or tangential forces. ...
... In different research work has been determined the connection experimentally, which justified it with the existence of micro-dispersions in the rigid body [1][2][3][4]. Furthermore it has been seen the immersion of the cylinder in the plane of motion as a property of material and geometry, which does not depend on load. According to the classical contact mechanics it has been found that the elastic deformation and the coefficient of friction in the roll d is depended from the load. ...
In this paper the generalized model of contact of two plan bodies that roll and slide or just roll is presented. The analytical solution of the correct distribution of pressure in the contact is realized in the presence of the normal compressive force, which realizes the contact, as well as of the force pair or of a tangential force. This model can be used on sprocket teeth due to sliding rolling or rolling itself on the gear pole. The results obtained have been experimentally confirmed by many researchers as well as by the damage that the wheels actually suffer from the teeth.
... In [31], using advanced computer technologies, functions are derived that provide interpreted information on the geometric changes of the track throughout its life cycle. ...
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.
... The most costeffective intervention can be if drainage is constructed correctly in these cases. In these cases, two side ditches are not enough; adequate drainage is highly needed from the plane of the substructure [17,18]. ...
Purpose. Justification of the feasibility of using new types of drainage materials, such as Concrete Canvas (CC), under the upper structure of the railway permanent way.
Methodology. The tasks were solved by a complex research method, including analysis and generalization of literary and patent sources, analytical, experimental studies, using computer and mathematical modeling methods. Tests were conducted with and without the CC layer in a multi-level shear box. After the shear test, the specimens were also tested for load-bearing capacity (E2, according to the Hungarian standard) and particle breakage. The contact surface between the bottom of the ballast and the CC was measured using a precision 3D laser scanner (GOM ATOS) and visualized graphically using AutoCAD software.
Findings. Experimental testing of the vertical load during connection and analysis compared with the test results of geocomposite/ geogrid structures, internal shear resistance, and other parameters proved the structure’s higher load-bearing capacity with the CC layer. Based on the results, the Concrete Canvas structure provides higher reinforcement than the average geogrid type.
Originality. The advantages of using new Concrete Canvas materials in the structure of a railway track have been demonstrated for the first time to provide greater internal shear resistance than the average for geogrids.
Practical value. These results may provide primary data for using Concrete Canvas in railway tracks and superstructures in the future.
... Modernization of the Hungarian track design regulations (unfortunately, in parts, there are more than 30-year old regulations [28]) and widespread use of the established "e-rail system" will be required in the future because track design speeds for these are not more than 160 km/hof course, in the relevant new harmonized European standard [29], it is possible to find design parameters that can also be applied to speeds of 300 km/h. The second most important aspect is that according to the theory of railway track degradation [30,31], someone must keep our railways in good technical condition during the current EU financing cycle (2021-2027) and in the future, taking into account that the expected lower amounts are to be spent on track rehabilitation because our high-quality reconstructed lines may face a similar fate without maintenance and maintenance funds as they did in the 1990s and 2000s. ...
The methodologies used to assess the inner shear resistance of granular layers from minerals measured in the laboratory with and without geosynthetic reinforcing layers are described in this paper. For the measurements, a multi-level shear box is applied without considering vertical loads on the top layer. In the literature and engineering practice, an accepted calculation method for determining inner shear resistance exists. It is the shear force with linear shearing speed, primarily after a peak force value. This can be accounted for in the present case by calculating the average force value for the 40-80 mm shear range using previous scientific and research achievements. The article details each possible additional method and compares it different methods. Three granular materials, as well as six planar geosynthetics, were studied. For this purpose, the results of 216 measurements were considered and processed using 61 different shear function-qualification parameters. The calculations were performed using a simplified function fitting test and a selection process to maximize the allowable relative standard deviations. All three types of materials and four classification parameters were chosen as references for comparability. As a result, only one alternative parameter can be used to determine the reinforcing-weakening values with a maximum deviation of 5% while not producing insufficient results in the placement (ranking) of the individual granular material and geosynthetic pairings. This parameter is the area under the function (integral) calculated on the measurement graph of the 40-80 mm shear range, in kN×mm unit; it gives correct values only if the reference granular material is the considered railway ballast, the shearing plane is the geosynthetic's plane (i.e., the so-called "0-plane"), and the reference qualification parameter is the original recommended parameter. The best relative standard deviation values were 20% and 30%.
... Many interests of the engineering researchers have been focused in the delicate contact problem in the area close to the forces for different engineering applications [1][2][3][4][5][6][7][8][9][10]. Contact mechanics has its application in many engineering problems. ...
Many of the engineering applications have faced the delicate contact problem in the area close to the forces where it is very difficult to experimentally carry out various measurements and draw important conclusions on the condition of the contact points. In this paper the forced state in the vicinity of the forces for the half-plane will be studied. Furthermore, the qualities displayed by the half-plane under the action of normal forces, tangential forces and the moment caused by a pair of forces will be analyzed, as well as changes in the elastic characteristics for the forced plane state and the deformed plane state.
... The quality control and the ballast layer influence on duration of the track lifetime are the subject of numerous studies and publications in recent years [1][2][3][4][5][6]. The investigations [7][8] have discovered a significant effect of the ballast layer consolidation and ballast filling on the construction of railroad engineering buildings. ...
The property of railway track to resist the irreversible deformation for a long-term operational loading considerably depends on the ballast layer. The ballast layer is the element of a railway track whose mechanical properties and state are formed in-situ with the help of the ballast cleaning, tamping and distributing machines. The varied properties of the ballast material to obtain the form during the maintenance and retain it during the operation are equally important for the ballast layer. The control over the processes of the ballast consolidation and deconsolidation by means of measurement methods could potentially provide great possibilities for improvement of its properties both during the maintenance and operation. The paper deals with an experimental study of the railway ballast consolidation and deconsolidation processes under the vibration loading of the sleeper. A non-destructive measurement method is proposed to investigate the distribution of the ballast consolidation along the sleeper. The method is based on the measurement of time of mechanical wave propagation. Modern low-cost sensors and powerful microcontroller techniques enable creating smart measurement systems for automatic multi-point data acquisition, online processing and statistical estimation of the ballast consolidation distribution.
... The influence of vibration characteristic analysis of ballast with different aspect ratios on ballast settlements is presented in [13]. Track geometry deterioration taking into account the influence of rail joints and other factors is studied in [14], [15]. ...
Railway ballast tamping is one of the cost-expensive renewal and maintenance works of railway superstructure. The quality of ballast consolidation influences its resistance to residual deformations and long-term deterioration of track geometry. The process of ballast compaction along the sleeper under the vibration loading is complex and depends on many factors. The ballast flow processes under the vibration loading can produce both consolidation and un-consolidation of ballast material. The present study is devoted to the experimental investigation of ballast consolidation inhomogeneity. The method of ballast local consolidation measurement is proposed. The method is based on the velocity of impact wave propagation that is measured with device. The application of modern microcontroller and sensor techniques provided simple and reliable multi-point velocity measurements in a ballast layer. That enables well enough spatial resolution of ballast consolidation inhomogeneity. The measurement analysis has shown more than 4 times higher consolidation under the sleeper center than for unconsolidated ballast.
... The quality control and the ballast layer influence on duration of the track lifetime are the subject of numerous studies and publications in recent years [1][2][3][4][5][6]. The investigations [7][8] have ...
The property of railway track to resist the irreversible deformation for a long-term operational loading considerably depends on the ballast layer. The ballast layer is the element of a railway track whose mechanical properties and state are formed in-situ with the help of the ballast cleaning, tamping and distributing machines. The varied properties of the ballast material to obtain the form during the maintenance and retain it during the operation are equally important for the ballast layer. The control over the processes of the ballast consolidation and deconsolidation by means of measurement methods could potentially provide great possibilities for improvement of its properties both during the maintenance and operation. The paper deals with an experimental study of the railway ballast consolidation and deconsolidation processes under the vibration loading of the sleeper. A non-destructive measurement method is proposed to investigate the distribution of the ballast consolidation along the sleeper. The method is based on the measurement of time of mechanical wave propagation. Modern low-cost sensors and powerful microcontroller techniques enable creating smart measurement systems for automatic multi-point data acquisition, online processing and statistical estimation of the ballast consolidation distribution.
... Plášeket al. (2015) studied the ballast settlements development of switch in the in-situ investigations. The research of the deterioration process due to inhomogeneous ballast settlements is presented in paper of Nagy (2017). The influence of track stiffness as well as many other parameters on inhomogeneous track settlements is considered in (Sysynet al., 2018). ...
Railway turnout is geometrically and physically inhomogeneous object of railway superstructure. The common crossing zone is the high-loaded part of turnout with relatively short lifecycle. The different degradation processes are taking place in the common crossing. On the one hand, the frog nose and wingrail are wearing with inhomogeneous intensity, on the other hand the ballast under the crossing zone is uniformly deformed that lead to appearing the void wave along the crossing axis. The two deterioration processes are interconnected and both influence the dynamic loading. The paper deals with research of both influences based on the mathematical modelling and simulation together with the analysis of inertial vehicle based measurements. The ballast settlements behavior is simulated with the numerical model and compared with the settlements measured with axle-box accelerations system. The current research makes the base for the following inertial diagnostic vehicle and track based investigations as well as planning the maintenance works at common crossing. © 2019 Institute for Transport Studies in the European Economic Integration. All rights reserved.
... • effects of other dynamic loadings (e.g. welts, rail joints, turnout frogs [34]- [39]); • effects of track geometry and its degradation [40]. ...
This article sums up the recent results in the topic of investigation of special procedure for evaluation railway ballast particles’ degradation. World’s railways are mainly conventional ballasted tracks. Railway ballast is the largest ‘mass’ in the superstructure. Enough quantity of railway ballast in adequate quality is needed to construct or maintain railway tracks. Nowadays that is a naturally fact to provide these requirements. However, due to the restrictions in the connected regulations and specifications (since 2010), Hungary has only few quarries, which are able to product adequate railway ballast material railway lines with speeds more than 120 km/h. The major aim of this research is to be able to simulate the real stress and strain circumstances related to ballast particles in laboratory and in modelling with discrete element method (DEM) software. This article introduces the assembly of performed laboratory test and recent test results. The authors sum up the current international literature review, detail their results from their laboratory tests.
... Other additional dynamic loading effect can't be neglected in sophisticated methods, e.g. surroundings of rail welts, rail joints, as well as switch frogs where higher ballast breakage should be expected [42,43,44,45,46]. ...
This paper contains some conclusions from the author’s research that the authors experienced during their individual fatigue laboratory tests.
The most railway lines in the world have so called traditional superstructure (ballasted tracks). In the past few years there were a lot of railway rehabilitation project in Hungary, as well as abroad. The authors think that it is important to learn about the process of ballast degradation, because ballast material is the largest weight in the track.
The authors’ research’s main goal is to be able to simulate the stress-strain effect of ballast particles in real and objective way in laboratory conditions as well as in discrete element modelling.
The authors have developed an individual laboratory test, but due its the enormous time requirement, they are trying other laboratory test as supplement.
The use of the available laboratory test tools has recently started as a new direction for the research topic. The authors worked out two types of test methods: one of that has wide range of literature, but for the other one there is no relevant source. The first method is based on 3-D scanning and image analysis, which can be used for examine one particle’s degradation and its surface change. For the second method a CT (computer tomograph or X-ray) device was used with a small aggregation.
Hopefully, adequate new results can be achieved with developing the new methods in the research
topic.
... dust, concrete sleeper abrasion, breakage, in case of water pockets the increase of fine particle content in the ballast bed because of evolving pumping effect due to repeated dynamic load, etc.); deterioration effect accelerated by substructure or superstructure defect; effects of other dynamic loadings (e.g. welts, rail joints, turnout frogs [27,28,29,30,31,32]); effects of track geometry and its degradation [33]. ...
This paper demonstrates the results in the research topic of the railway ballast particles’ breakage test with unique laboratory test. The most railway lines in the world have so called traditional superstructure (ballasted tracks). In the past few years there were a lot of railway rehabilitation projects in Hungary, as well as abroad. Nowadays cannot be expected that there is enough quantity of railway ballast in adequate quality, because of the modifications and restrictions in the related regulations in Hungary since 2010. In Hungary there are only a few quarries which are able to ensure adequate railway ballast material for construction and maintenance projects for speed values between 120 and 160 km/h. This may cause supply and quality risk in production of railway ballast. The authors’ research’s main goal is to be able to simulate the stress-strain effect of ballast particles in real and objective way in laboratory conditions as well as in discrete element modelling.
... there is hardly no breakage in the ballast shoulder, etc.); only 225 kN axle load was taken into consideration (it is true for freight trains, for passenger trains about 180 kN value would be more realistic); effects of other dynamic loadings (e.g. welts, rail joints, turnout frogs [34]- [39]); effects of track geometry and its degradation [40]. This paper introduced the research problem related to railway ballast particle degradation and sentenced that a newly developed laboratory testing method can be adequate for measure and evaluate ballast materials' breakage using dynamic pulsating load (fatigue). ...
Link: https://akademiai.com/doi/pdf/10.1556/606.2019.14.2.1
This paper summarizes the authors’ up-to-date results in the research topic of railway ballast particles’ breakage test with individual laboratory test. In the past few years there were a lot of railway rehabilitation and maintenance project in Hungary, as well as abroad. The largest part of world’s railways has traditional superstructure, i.e. they are so called ballasted tracks. The railway ballast is the highest mass in the railways’ superstructure. Nowadays, it is a naturally fact that there is enough quantity of railway ballast in adequate quality. However, due to the modifications and restrictions in the related regulations since 2010, there are only few quarries in Hungary, which are able to ensure adequate railway ballast material for railway construction and maintenance projects for speed values between 120 and 160 km/h. Quarrying industry is stricken by aggravated environmental, heritage and conservation regulations year by year, it limits the accessibility of mineral wealth in significant manner. This fact with quality requirements means supply and quality risk in production of railway ballast in medium term. The main goal of authors’ research is to be able to simulate the stress-strain effect of ballast particles in real and objective manner in laboratory circumstances, as well as in discrete element method modeling. This paper introduces the exact assembly of executed laboratory test and newest test results. The authors summarize the up-to-date international literature review, using that they give short outlook to the planned research with research directions in near future.
... It is well known that degradation of ballast particles can be occurred: the uniform stress distribution in the interface of down surface of sleeper and ballast bed, as well as in the interaction of ballast particles is not true at the dimensioning and design of track structure layers and elements [10], particles are not loaded by static forces but dynamic, pulsating, repeating (with more million cycles) forces during railway operation, which stress can be evolved impulse-like stress (e.g. in case of damage (failures) of rail ends, weldings) and can reach the plurality of static one [11,12]. It can accelerate the deterioration process [13], in reality there are very high stresses in the interface of sleepers and ballast particles, as well as between particles that increases the breakage (degradation) of particles [10], the contact stresses mentioned above can be decreased by usage e.g. under sleeper pads, or polyurethane foam or bitumen stabilised ballast [7]. ...
A new laboratory test procedure was developed to be able to evaluate railway ballast particle degradation using dynamic fatigue test. There is a product standard (MSZ EN 13450:2003) that contains requirements for mechanic parameters of railway ballast, e.g. Los Angeles as well as Micro- Deval abrasion, according to MSZ EN 1097-2:2010 and MSZ EN 1097-2:2012 standards, respectively.
These laboratory tests give the abrasion parameters of railway ballast (as well as other type of rocks, e.g. concrete, asphalt pavement, etc.) in the consideration of a rotating steel cylinder (railway ballast material has to be put into it) using steel balls, water or without them. In real circumstances this type of stress can never occur in railway tracks.
The mentioned new laboratory test procedure is able to simulate more precisely the real stress and degradation of ballast particles. The calculation of degradation is in accordance with the methods written in international literature. The required time interval of ballast cleaning can be determined, too.
The authors summarize the results of international researches, scientific papers and books related to laboratory degradation tests of railway ballast, as well as real field tests in tracks. Relevant parameters, statements are described, after it has been competed, own laboratory test programme and assembly are introduced and detailed.
This paper contains the results of a laboratory test series related to specific railway ballast breakage evaluation method using laboratory measurement solution. Five types of andesite railway ballast sample were tested by dynamic pulsating force with three million load cycles that simulates approximately 4-year-loading in reality (e.g. MÁV No. 1. railway line).
The authors detail their future research programme that will be performed in 2018, this research is supported by the ÚNKP-17-4 New National Excellence Program of Ministry of Human Capacities.
... The experimental polymercomposite joints and the assigned control joints (due to comparability) were built into the track in four different places, with three different rail profiles, in three different speed categories (Biatorbágy, Tatabánya, Győr, Lébény-Mosonszentmiklós railway stations) in the No. 1 main railway line (Kelenföld-Hegyeshalom) in Hungary. (The speed of trains and the track geometry mainly influences the dynamic effects and the deterioration process [4][5][6][7].) The authors investigated and made diagnostics of experimental fibre-glass reinforced fishplated and control steel fishplated rail joints. This paper resulted the topics below: ...
After laboratory tests (shear tests of glue materials, 3-point-bending tests, axial pull tests), as well as field inspections, trial polymer-composite and control (steel) fishplated glued insulated rail joints were built into railway tracks with (almost) the same border conditions (rail profiles, cross section parameters, track condition, etc.). Now these trial and control rail joints there are in the No. 1 main railway line (Kelenföld-Hegyeshalom) in Hungary at four different railway stations: Biatorbágy, Tatabánya, Győr and Lébény-Mosonszentmiklós. In this paper the authors summarize the assessment and results of track geometry measurements (geometry recording car and rail straightness tests) in the accordance with the variation of state of the inspected glass-fibre reinforced, as well as steel (control) fishplated glued insulated rail joints. When evaluating the measurement results which based on the geometry recording car data (only longitudinal settlement values) and the railhead straightness tests. In this article the authors conceive statements about the condition changes of the surroundings of the measured railway joints. During the evaluation of longitudinal settlement values the data per 25 cm have been filtered and were shifted along the longitudinal section to 30 meter basis length. The percentage distribution of the number of errors were examined in 30 meter long section for both of rails, separately, and the absolute value of average of the parameters regarding to both rails, and the calculated condition characteristic numbers were represented in a graph. For evaluation of railhead straightness tests the measurement results have been investigated related to the area below the curves (integer), and the areas have been compared and depicted in graph depending on the rolling gross tons in case of the roughness of the guiding edge and the running surface of railhead. The evaluation of results were rated according to the current condition of the investigated sites. This research is supported by the EFOP 3.6.1-16-2016-00017 project.
During the examination of the Hungarian national network for the period from the 2nd half of 1999 to the 2nd half of 2013, had to answer to the reason why the geometrical errors are able to decrease, despite the fact that no regulation intervention was done on the line section during the study period. This anomaly leads us to the procedure in which it became important to determine the accuracy of the FMK-004 measuring car (FMK in English: railway superstructure measuring car). With the VBA code written for the research task, the data set was optimized, then deterioration functions were fitted to the data, and where outliers were detected, the extent of the outlier was analysed on a statistical basis. This determines the measurement accuracies for each of the three metrics separately. Furthermore, it can be clearly demonstrated by the examination of the national network that in 90% of cases there is a series of geometrics that have a value that decreases compared to the previous half-year, while other geometrics value still is increasing.
Мета. У цій статті передбачено визначити поведінку ізольованих рейкових з’єднань із полімер-композитними накладками без склеювання під час розгляду динамічних навантажень щодо власних лабораторних випробувань. Автори представляють прикладні можливості вимірювання. Методика. Динамічні (втомні) випробування на вигин було проведено за допомогою ізольованих рейкових з’єднань, зібраних із пластикових полімерних рейкових накладок. Спеціальні лабораторні випробування пов’язані з технікою вимірювання та методом оцінки цифрового зображення/відео, що виконані апаратними і програмними засобами GOM, а також з комп’ютерною томографією відповідно до лабораторних випробувань на вигин. Результати. У попередніх роботах автори публікували результати дослідження клейових рейкових стиків, зараз вони продовжують дослідження рейкових стиків із пластиково-полімерними накладками без склеювання. Було випробувано два різних типи рейкових накладок, виготовлених із полімерно-пластикового матеріалу. Для рейкових стиків із накладками без склеювання автори використали спеціальні методи вимірювання, розроблені GOM (Tritop, Aramis), які дозволяють застосовувати високоточні цифрові вимірювання з вражаючими результатами візуалізації. Записи комп’ютерної томографії забезпечують можливість отримувати інформацію про внутрішні тріщини та пошкодження пластиково-полімерних рейкових накладок, а також про вимірювання з високою точністю. Метод оцінки повинен бути розроблений для цих конкретних методик вимірювання, щоб мати можливість порівнювати результати і визначати наукові твердження. Наукова новизна. До цього часу дослідники й дослідницькі групи займалися вивченням ізольованих рейкових стиків зі спеціальними пластиково-полімерними накладками без склеювання, застосовуючи згадані спеціальні методи; ніхто не визначав точний процес руйнування цих з’єднань, а також явище збільшення тріщин у поперечному перерізі рейкових накладок. Практична значимість. Дослідницька група авторів мала можливість ознайомитися з деталями рейкових накладок, посилених скловолокном, склеєних смолою під час лабораторних випробувань, а також опублікувати своєчасну інформацію про результати лабораторних випробувань. Ці результати в майбутньому можна застосовувати в залізничному машинобудуванні на всіх етапах: проєктування, будівництво, технічне обслуговування й експлуатація.
Purpose. The most railway lines in the world have so called traditional ballasted superstructure. The authors think that it is important to learn about the process of ballast degradation. There are only two types of standardized laboratory test methods in the EU to assess railway ballast particle degradation and describe the rock physic characteristics, but are not suitable for modelling the railway stress-strain circumstances of ballast materials, and they particles. In this paper the authors represent some conclusions from their research that the authors experienced during their individual fatigue laboratory test and from new additional tests. With these kind of testing methods, the deterioration process of railway ballast particles can be assessed more realistic and precisely. Methodology and new directions. There are two types of laboratory tests which are presented in this article. The first one was performed by using a shear box with a special layer structure that is loaded by dynamic, pulsating force; while the second one was executed by using a 140 mm diameter HDPE tube with its original closing element that is loaded by ZD-40 machine. Findings and problems. There is a development after the R&D work made and published in 2014, in 2017 and 2018 years the ballast particle deterioration process is given according to more intermediate fatigue cycles with individual measurements that show more precise «picture» about the full particle degradation, i.e. breakage process. The authors give more accurate correlation functions between the calculated parameters and load cycles during fatigue. However, there are many factors in the test that need to be improved in the future. Therefore, the authors have discovered other additional tests. Originality. The most important goal of the authors that supplement the currently used regulation with new measurement methods. Practical value The authors’ developed and new methods may serve as a basis for a future instruction or regulation. The publishing of this paper was supported by EFOP 3.6.1-16-2016-00017 project.
Purpose. The authors’ aim is to evaluate more precisely the deterioration process of glued insulated rail joints with polimer-composite and steel fishplates regarding to own laboratory tests. Methodology. The laboratory tests were executed by three-point static and three-point dynamic (fatigue) bending tests’ measurement results related to glued insulated rail joints with fibre-glass reinforced polymer-composite fishplates (brand: APATECH). During the research the static three-point bending tests were performed on rail joints assembled with three different rail profiles (MÁV48, 54E1 (UIC54) and 60E1 (UIC60)) with three specimens, measured on 13 different support bay values before fatigue test, as well as after 3.5 million loading cycles (the degradations process was checked after every 0.5 million cycles) on polymer-composite and steel fishplated rail joints. Findings. The investigation of fiber-glass reinforced and steel fishplated rail joints (three-point static and dynamic bending laboratory tests) are in progress. Considering to them, the mechanical deterioration processes were able to be determined by measurements of deflection values compared to original ones (i.e. before fatigue tests). The differences can be pointed out by analysis of measurement results related to both types of glued insulated rail joints (steel and polymer-composite fishplated ones). Originality. The goal of this research is to investigate the application of this new type of glued insulated rail joint and to determine the ultimate lifetime of the investigated rail joints, e.g. how much time they can be safely held in the railway track without damage. In the international literature no one has investigated this field of glued insulated rail joints. Practical value. The fibre glass reinforced resin-bonded fishplated glued insulated rail joints and ‘control’ steel fishplated glued insulated rail joints were built into railway line (between Kelenföld and Hegyeshalom state border) in Hungary at three different locations. In this article the investigation of deterioration process of glued-insulated rail joints and steel fishplated glued insulated rail joints are demonstrated only by laboratory bending tests.
Purpose. There are special, standardized laboratory test methods to evaluate railway ballast particle breakage; they are the Los Angeles and the Micro-Deval abrasion test. The authors opine that these methods aren’t the most adequate methods to assess the real ballast particle degradation because in reality never occurs these kinds of stresses and strains (i.e. particles in a rotating drum with or without steel balls and with or without water). A new laboratory test procedure is needed. The authors attempted to configure an adequate one in 2014, it is detailed in the paper, as well as the initial results and improvement possibility. This test method is related to dynamic pulsating test, the particle size distributions (PSD) had to be determined before and after fatigue. In 2017-2018 the research is supported by ÚNKP-17-4 program. Methodology. Multi-level steel box is utilized with a special layer structure, detailed in the paper. Five different types of railway ballast samples were tested. PSDs were defined, and regarding to the results relationship between ballast particle degradation values (according to Los Angeles and Micro-Deval abrasion tests, as well as this newly developed laboratory test method) was searched, as well as time interval between necessity railway ballast cleaning work was also calculated. Findings. The authors sentenced the results regarding to the self-developed laboratory test method that is able to assess the particle degradation and time interval between railway ballast cleaning work more precisely related to the real railway operation circumstances. Relationship was determined between particle breakage according to standardized and unique (non-standardized) laboratory test methods. Originality. The paper summarized the results a newly developed laboratory test method for evaluation of the degradation of railway ballast particles. Practical value. It sentenced the possibility to improve the measurements and assessments regarding to the research phase supported by the ÚNKP-17-4 project.
A uniform track condition assessment model, which is based on both visual inspection and automatic under load track geometry measuring system, is needed to reduce maintenance cost and increase safety and ride comfort for passengers. A tramway track condition assessment model as well as a geographical information system are worked out by the Author (implementation in progress) for Budapest tram lines to detect and predict rail defects and plan the effective maintenance work. The developing method determines the track condition on the basis of visual inspection and in-service vehicle's wheels-mounted accelerometers.
The technical specifications of D.12/H of Hungarian State Railways specifies that a continuously welded rail track can be constructed through a bridge without being interrupted if the expansion length of the bridge is no longer than 40 m. If the expansion length is greater than 40 m, rail expansion joints have to be constructed.
The aim of the research is to create finite-element models with which the interaction of continuously welded rail track and steel railway bridges can be calculated and to provide technical solutions of track structures on bridges with ballasted track so rail expansion joints can be omitted.
There is a great interest to predict the long- term evolution of the track irregularities for a given track stretch of the high-speed train network, in order to be able to anticipate the start off of the maintenance operations. In this paper, a stochastic predictive model, based on big data made up of a lot of experimental measurements performed on the French high-speed train network, is proposed for predicting the statistical quantities of a vector-valued random indicator related to the nonlinear dynamic responses of the high-speed train excited by stochastic track irregularities. The long- term evolution of the vector-valued random indicator is modeled by a discrete non-Gaussian nonstationary stochastic model (ARMA type model), for which the coefficients are time-dependent. These coefficients are identified by a least-squares method and fitted on long time, using experimental measurements. The quality assessment of the stochastic predictive model is presented, which validates the proposed stochastic model.
Department of Railway Engineering realizes monitoring of the experimental section with various constructions of the railway superstructure; experimental section consist of the standard structure of railway superstructure on earthworks and in the concrete channel and slab track structure in tunnel, on bridges and on earthworks. Diagnostics is comprehensively focused on the quality of effective position of the track, structural and geometric structure of the track and on the quality of the elements of the superstructure. Relevant design and geometrical parameters of the track are the track alignment, track top, gauge, superelevation and twist. The paper presents the results of diagnostics and graphical overview of the development of quality parameters.
Railway maintenance planners require a predictive model that can assess the railway track geometry degradation. The present paper uses a Hierarchical Bayesian model as a tool to model the main two quality indicators related to railway track geometry degradation: the standard deviation of longitudinal level defects and the standard deviation of horizontal alignment defects. Hierarchical Bayesian Models (HBM) are flexible statistical models that allow specifying different spatially correlated components between consecutive track sections, namely for the deterioration rates and the initial qualities parameters. HBM are developed for both quality indicators, conducting an extensive comparison between candidate models and a sensitivity analysis on prior distributions. HBM is applied to provide an overall assessment of the degradation of railway track geometry, for the main Portuguese railway line Lisbon–Oporto.
The paper deals with the research and development of the authors related to investigation of geogrid railway ballast reinforcement. It summarizes the theory of the geometrical deterioration of railway tracks, as well as the advantages of the use of geogrid reinforced ballast in railway superstructure. This article summarizes the result of the field tests with five different geogrid types on a Hungarian main railway line and laboratory multi-level shear box tests. It points out to future research possibilities, for example the modelling of laboratory multi-level shear box tests with discrete element method that may certify their results.
There are no design parameters related to speeds exceeding 160 km/h in the effective Hungarian railway design rules. In the relevant international standard (ENV 13803) a similar speed limit is 300 km/h. This paper deals with the comparative of these regulations. Parameters of two transition curves used in Hungary and other used in Austria are determined. The importance of the new design parameters provided by ENV 13803 is assessed. It is demonstrated that the usability of the clothoide transition curves is unnecessarily restricted for the speeds v ≤120 km/h in the Hungarian regulations.
Railway operations are inherently complex and source of several problems. In particular, track geometry defects are one of the leading causes of train accidents in the United States. This paper presents a solution approach which entails the construction of an ensemble classifier to forecast the degradation of track geometry. Our classifier is constructed by solving the problem from three different perspectives: deterioration, regression and classification. We considered a different model from each perspective and our results show that using an ensemble method improves the predictive performance.