Application of data mining techniques for the investigation of track geometry and stiffness variation

Author(s):  
Mohammad Mehrali ◽  
Morteza Esmaeili ◽  
Saeed Mohammadzadeh

Railway tracks are one of the most important national assets of many countries. The major part of the annual budget of railway companies concerns repairing, improving, and maintaining railway tracks, which is a challenge for railway managers. The logical method of repair and maintenance should take into account all the economic and technical aspects of the problem and proper management of track maintenance—without knowing the factors and parameters responsible for the track failure—quality control methods, and finally, the choice of the appropriate repair methods. Railway track geometry is the main factor that identifies the track behavior and condition. It is based on measuring the geometric parameters of the track determined by the track quality indices. The existing track quality indices mostly represent the geometrical condition of the railway track superstructure. In the past years, the effects of track bed stiffness on the track condition have been investigated. This paper investigates the railway track condition based on the railway track geometry parameters as well as the vertical track stiffness. A method for continuous measurement of track stiffness along a railway line is described and demonstrated. By measuring the track geometry parameters and stiffness, the superstructure and the substructure condition of the railway track are assessed. In addition, the relation between these data is investigated by using data mining techniques such as classification, decision tree, clustering, and dominant wavelength filtering. It is shown that filtering the data based on the dominant wavelength provides the best correlation between the track geometry in the vertical direction and stiffness.

2020 ◽  
Vol 10 (23) ◽  
pp. 8490
Author(s):  
Stefan Offenbacher ◽  
Johannes Neuhold ◽  
Peter Veit ◽  
Matthias Landgraf

Adequate railway track condition is a prerequisite for safe and reliable railway operation. Many track quality indices (TQIs) have been developed with the aim of assessing the track condition holistically. These indices combine measurement signals of some or all relevant geometry parameters with different mathematical models. In this paper, a selection of important TQIs is evaluated. Using measurement data of a five kilometer track section, the indices are calculated and their properties are discussed. This study reveals that all indices exhibit drawbacks to varying degrees. As a consequence, a new index has been developed—the track quality index of Graz University of Technology (TUG_TQI). Its favorable characteristics are presented by means of the above-mentioned test section. The TUG_TQI combines all relevant track geometry parameters, which are normalized beforehand to eliminate over or underrepresentation of different parameters. Thus, the index reliably describes the overall geometrical track quality.


2018 ◽  
Vol 10 (0) ◽  
pp. 1-7
Author(s):  
Vytautas Motiejus Bubnelis ◽  
Benas Slepakovas ◽  
Laura Černiauskaitė ◽  
Henrikas Sivilevičius

Rail transport, in competition with other modes of transport, has to improve the quality of passenger and freight transport. In order to carry passengers and goods quickly, efficiently and safely, it is necessary take maintenance railways so that their geometric parameters do not exceed the tolerances. About real railway track condition, the data is obtained by track geometry recording car, measuring seven geometric parameters dispersion. This paper presents the methodology for determining and estimating the geometric parameters of the track geometry, which shows that the track quality index (TQI) is the sum of the variance of seven geometric parameters. Experimental research on the two-track A (8km) and B (11km) a three-year period (2015-2017) for all 12-month KKI, establish their quality dynamics (change over time). These data indicate that the quality of the analyzed sections A and B was good, but due to the increasing mass (in megatons) of transported loads, there is a tendency to deteriorate. Santrauka Geležinkelių transportas, konkuruodamas su kitomis transporto rūšimis, privalo gerinti keleivių ir krovinių vežimų kokybę. Norint greitai, efektyviai ir saugiai vežti keleivius ir krovinius, būtina taip prižiūrėti geležinkelių kelius, kad jų geometrinių parametrų nuokrypiai neviršytų leidžiamųjų nuokrypių. Apie tikrąją geležinkelių kelio būklę duomenys gaunami kelmačiu išmatavus septynių geometrinių parametrų sklaidą. Šiame darbe pateikta geležinkelio kelio geometrinių parametrų sklaidos nustatymo ir vertinimo metodika, kurioje įrodyta, kad kelio kokybės indeksas (KKI) yra septynių geometrinių parametrų dispersijų suma. Eksperimentiškai ištyrus dviejų geležinkelio kelių A (8 km) ir B (11 km) trijų metų laikotarpiu (nuo 2015 iki 2017 metų) visų 12 mėnesių KKI, nustatyta jų kokybės dinamika (kaita bėgant laikui). Šie duomenys rodo, kad ištyrinėtų A ir B ruožų kelio kokybė buvo gera, bet dėl didėjančios pervežtų krovinių suminės masės (megatonų skaičiaus) turi tendenciją blogėti.


Author(s):  
Alireza Roghani ◽  
Renato Macciotta ◽  
Michael Hendry

The serviceability of a section of railway highly depends on track stiffness and roughness. Railway operators regularly measure parameters associated with track stiffness and roughness to evaluate the track conditions. These measures are used in combination with performance observations to assess maintenance requirements. Although these assessments are mostly qualitative, railway operations have benefited from them. Railway operators keep comprehensive records of different types of track defects along their lines. These records are a measure of track performance and present an opportunity to quantify the relationship between track quality and performance. This brings the possibility of developing a performance-based approach for assessing the maintenance requirement along a railway track. In this paper, a database of track geometry defects along Canadian National Railway’s Lac la Biche subdivision (Alberta) has been compared against measured parameters associated with track roughness and stiffness. The analyses confirm the relationship between track stiffness and roughness, and the occurrence of track defects. This relationship is further used to define threshold values of track roughness and stiffness, and a hazard chart for maintenance requirements along the Lac la Biche subdivision is proposed.


Author(s):  
I Grossoni ◽  
AR Andrade ◽  
Y Bezin ◽  
S Neves

With rapid advances in sensor and condition monitoring technologies, railway infrastructure managers are turning their attention towards the promise that digital information and big data will help them understand and manage their assets more efficiently. In addition to the existing track geometry records, it is evident that track stiffness is a key physical quantity to help assess track quality and its long-term deterioration. The present paper analyses the role of track stiffness and its spatial variability through a set of computational experiments, varying other vehicle and track physical quantities such as vehicle unsprung mass, speed and track vertical irregularities. The support stiffness conditions are obtained using a sample procedure from an autoregressive integrated moving average model to generate a representative larger set of data from previously on-site measured data. A set of computational experiments is carefully designed, varying different physical variables, and a vehicle–track interaction model is used to estimate the track geometry deterioration rates. A series of log-linear regression models are then used to analyse the impact of the tested physical variables on the track deterioration. The main findings suggest that the spatial variability of track stiffness significantly contributes to the track deterioration rates, and thus it should be used in the future to better target the design and maintenance of railway track. Finally, a comparative study of some settlement models available in literature shows that they are very dependent on the test conditions under which they have been derived.


2020 ◽  
Vol 6 ◽  
Author(s):  
Mikko Sauni ◽  
Heikki Luomala ◽  
Pauli Kolisoja ◽  
Esko Turunen

2020 ◽  
Vol 10 (9) ◽  
pp. 3091 ◽  
Author(s):  
Chayut Ngamkhanong ◽  
Chuah Ming Wey ◽  
Sakdirat Kaewunruen

Nowadays, timber sleepers are still used for ballasted railway tracks to carry passengers and transport goods. However, the process of natural decay causes the problem of timber sleeper degradation over time. A temporary “interspersed” approach is used to replace rotten timbers with concrete sleepers. This implementation has several inadequacies, as interspersed railway tracks have inconsistent stiffness and experience significant deterioration over the years. Increased heat due to the change in the global climate can induce a compression force in the continuous welded rail (CWR), leading to a change in track geometry called “track buckling”. A literature review shows that track buckling on plain tracks has been widely studied. However, the buckling of interspersed tracks has not been fully studied. This study presents 3D finite element modelling of interspersed railway tracks subjected to temperature change. The effect of the boundary conditions on the buckling shape is considered. The obtained results show that the interspersed approach may reduce the likelihood of track buckling. This study is the world’s first to investigate the buckling behaviour of interspersed railway tracks. The insight into interspersed railway tracks derived from this study will underpin the life cycle design, maintenance, and construction strategies related to the use of concrete sleepers as spot replacement sleepers in ageing railway track systems. The outcome of this study will help track engineers to improve the inspection of the lateral stiffness of interspersed tracks in areas prone to extreme temperature.


Author(s):  
R. K. Liu ◽  
P. Xu ◽  
Q. X. Sun

During train runs, the interaction between train wheels and the rail track underneath makes track geometry change, which in turn results in all kinds of track irregularities. After the 6th train speed raise of China in 2007, railway transportation has shown three main new features: speed-raised, heavy-loading and high-density. Under these features, changes in railway track irregularities of China have also presented some new characteristics: higher deterioration rates of track irregularities and more frequent occurrences of track exceptions. To ensure the train operational safety and increase the transportation service quality, the preventive inspection and maintenance of railway track facilities have been put forward once again by railway maintenance departments of China. A precondition for the preventive inspection and maintenance is about how to accurately evaluate and predict the future track condition according to the historical track inspection data. In this paper, based on the characteristics of track irregularity changes and in accordance with the calculus thinking, we have developed a short-range prediction model called SRPM. The model uses track waveform data generated by the track geometry car (TGC) to predict track irregularities of a unit track section with the length of 100m for each day in a future short period of time. An algorithm for using SRPM to predict track irregularities has also been designed. According to the designed algorithm, using ORACLE database and computer program languages, we have programmed a computer software named P-SRPM. We then used P-SRPM to deal with 25 sets of TGC-generated track waveform data from the up going track of the Beijing-Shanghai railway (Jing-Hu railway) administrated by Jinan Railway Bureau (JRB) and predicted track irregularities of unit sections in the railway track segment. Finally, errors in these predictions were analyzed in both temporal and spatial dimensions. From the error analysis results, we come to the conclusion that SRPM can fairly accurately make short-range predictions for track irregularities of each unit section in the JRB-administrated Jing-Hu railway track (up going).


Author(s):  
Kirk M. Scanlan ◽  
Michael T. Hendry ◽  
C. Derek Martin

Railway regulators require that track geometry measurements meet a specific set of minimum safety thresholds. A proper interpretation of track geometry survey data is fundamental for the detection of track exceeding these thresholds and in need of corrective maintenance. Irregular track geometry independent of the minimum safety thresholds can also be used as evidence of degradation in the railway foundation. Therefore, multiple evaluation methods must be applied to the track geometry survey data when assessing foundation degradation. In this study, we compare multiple track geometry evaluation methods in order to assess if they equally identify sections of irregular track geometry along a 335 kilometer section of a Canadian freight railway. The track geometry evaluation methods investigated are the Transport Canada Class 5 minimum safety threshold exceedances and three literature-suggested track quality indices; the Overall Track Geometry Index, the Polish J Index and the Swedish Q Index. Furthermore, this study also investigates the ability of the track quality indices to provide additional insight into track geometry variability in sections without a minimum safety threshold exceedance. The track under investigation is not a Class 5, however, Class 5 minimum safety thresholds were used to produce enough threshold exceedances to allow for the comparison to the track quality indices. The results of the analysis reveal that while the large-scale variability in the three track quality indices is similar, the individual equivalency with the occurrence of Class 5 threshold exceedances is highly variable. Furthermore, only the Overall Track Geometry Index demonstrates the potential to provide consistent additional track geometry variability information.


2021 ◽  
Vol 1200 (1) ◽  
pp. 012018
Author(s):  
Shanmugasekar Thenappan

Abstract The track stiffness is the primary function of roadbeds thickness and subgrade characteristics. For this purpose, numerical scale track finite element technique representing the ballasted track with multi layered substructure founded on subgrade was simulated. The track deflection, stress was abstracted in static and dynamic conditions. The track significant design parameters: Foundation modulus, rail fatigue strength, rail bending stress and stress on subgrade levels were evaluated by using improved current track design numerical methods and compared against field test results which were carried out on part of MG Double track high speed main line (1600 km). Mathematical equations were developed to correlate the variables; ballast thickness, settlement, track stiffness, rail bending stress and rail fatigue strength on varying subgrade soil modulus. Incorporation of this parametric study will improve and optimise the conventional track design and maintenance standard. A simple improved track design was introduced by using single track stiffness parameter from conventional plate bearing test (PBT) on Force Displacement (FD) conventional curve method. The improved method with deriving equivalent track stiffness from rail pad and track substructure tested C value are accurate and simple. The current test method to determine the track stiffness in live track condition is expensive and unsafe with operational requirements. This PBT is simple, cost saving on labour, safe and without applying live train load.


Transport ◽  
2017 ◽  
Vol 33 (2) ◽  
pp. 555-566 ◽  
Author(s):  
Andrzej Chudzikiewicz ◽  
Roman Bogacz ◽  
Mariusz Kostrzewski ◽  
Robert Konowrocki

The aim of this paper is to demonstrate the possibilities of estimating the track condition using axle-boxes and car-bodies motions described by acceleration signals. In the paper, the results presented indicate the condition of tracks obtained from the preliminary investigation on the test track. Furthermore, the results from the supervised runs (on Polish Railway Lines) of Electric Multiple Unit (EMU-ED74) with the prototype of track quality monitoring system installed on-board are described. As Track Quality Indicator (TQI) algorithm, used in the mentioned prototype, a modified Karhunen–Loève transformation is used in preliminary preparation of acceleration signals. The transformation is used to extract the principal dynamics from measurement data. Obtained results are compared to other methods of evaluating the geometrical track quality, namely methods, which apply the synthetic coefficient Jsynth and five parameters of defectiveness W5. The results from the investigation showed that track condition estimation is possible with acceptable accuracy for in-service use and for defining cost-effective maintenance strategies.


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