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14 pages, 9788 KiB

Open AccessArticle

Current-Signal-Based Fault Diagnosis of Railway Point Machines Using Machine Learning

by Ahmad Sugiana, Willy Anugrah Cahyadi and Yasser Yusran

Appl. Sci. 2024, 14(1), 267; https://doi.org/10.3390/app14010267 - 28 Dec 2023

Viewed by 761

Abstract

The majority of railway operators still implement conventional maintenance for railway point machines (RPMs), which is one of the most vital pieces of equipment for ensuring the safety of train operation. The conventional maintenance method lacks accuracy, is less efficient, and has high [...] Read more.

The majority of railway operators still implement conventional maintenance for railway point machines (RPMs), which is one of the most vital pieces of equipment for ensuring the safety of train operation. The conventional maintenance method lacks accuracy, is less efficient, and has high labor costs. This study developed a cost-effective and accurate fault diagnosis (FD) method based on current data to increase the overall efficiency of RPM maintenance. The FD method for RPM equipment discussed in this paper consists of three working conditions: normal, working, and failure. The method was proposed based on time-series current signals, which were gathered when the RPM was in operation. Time-series data were extracted and filtered using time-domain feature extraction based on scalable hypothesis testing. The selected features became the datasets for machine learning modeling. Six machine learning algorithms were compared in order to find the algorithm with the best FD accuracy. The results showed 100% accuracy for the Decision Tree and Random Forest algorithms in the FD method. The results of the FD method could be important for maintenance teams in determining suitable maintenance activities based on RPM working conditions. Full article

(This article belongs to the Special Issue Railway Infrastructures Engineering: Latest Advances and Prospects)

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24 pages, 10171 KiB

Open AccessArticle

A Multi-Depth Deflectometer/Global Navigation Satellite System Method for Measuring Concrete Slab Track Deformation

by Pierre Anthyme Bahati, Viet Dinh Le and Yujin Lim

Appl. Sci. 2024, 14(1), 82; https://doi.org/10.3390/app14010082 - 21 Dec 2023

Viewed by 683

Abstract

This study introduces a Multi-Depth Deflectometer (MDD) combined with a Global Navigation Satellite System (GNSS) which was developed for measuring the deformation of railway slab track layers. We newly designed the MDD with the addition of laser sensor modules for increasing precision in [...] Read more.

This study introduces a Multi-Depth Deflectometer (MDD) combined with a Global Navigation Satellite System (GNSS) which was developed for measuring the deformation of railway slab track layers. We newly designed the MDD with the addition of laser sensor modules for increasing precision in which the MDD head is fixed at the top of the track slab. The MDD/GNSS system can measure the relative deflection between each track layer as well as the total deflection at the top of the track slab, which makes it possible to evade the fixed condition problem of classical MDD. The new MDD/GNSS system was installed at the transition zone between a tunnel entrance and its embankment, which experienced high settlement levels prior to repair. The system was used to monitor whether the repaired concrete track foundation with pressurized cement grouting was stabilized effectively and what track layer position was most unstable so that it had the most influence. The GNSS system was designed and built for computing net settlement at each track layer even when the MDD could not be fixed firmly at the end point, which is a major drawback of classical MDD. The results obtained from MDD and GNSS measurements indicated significant potential in aiding railway track settlement measurements. Full article

(This article belongs to the Special Issue Railway Infrastructures Engineering: Latest Advances and Prospects)

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25 pages, 13603 KiB

Open AccessArticle

Evaluation of Structural Stresses of Mountain-Embedded Railway Systems

by Hochan Lee, Sang-yun Han, Jeonghyeon Lim, Kiyoung Eum, Seungjun Kim and Young Jong Kang

Appl. Sci. 2023, 13(20), 11469; https://doi.org/10.3390/app132011469 - 19 Oct 2023

Viewed by 956

Abstract

Mountain railways are constructed on terrains with steep gradients and operate under unique conditions as they climb slopes at low speeds using rack rails. Recently, mountain railway systems in the form of embedded rail systems (ERSs) have been developed to minimize environmental damage [...] Read more.

Mountain railways are constructed on terrains with steep gradients and operate under unique conditions as they climb slopes at low speeds using rack rails. Recently, mountain railway systems in the form of embedded rail systems (ERSs) have been developed to minimize environmental damage caused by the construction of new roads. However, the use of ERS in mountain railway tracks is still limited, and research on their safety and behavior is lacking. Therefore, this study was conducted to evaluate the safety profile and behavioral responses of mountain-ERS under a steep gradient condition of 180‰. The effects of using high-strength concrete materials for precast concrete panels were investigated in this study, and the safety profile and behavioral response of mountain-ERS based on changes in the gradient and after adjusting the thickness of the subgrade of mountain-ERS was assessed. Under load conditions, the maximum tensile stress in the concrete elements did not exceed the tensile strength of the concrete. In the structural behavioral analysis, the patterns of stress variation were analyzed by applying stress to the concrete elements. The safety assessment and behavioral analysis results obtained in this study are considered valuable foundational research data for analytical studies on mountain-ERSs. Full article

(This article belongs to the Special Issue Railway Infrastructures Engineering: Latest Advances and Prospects)

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31 pages, 4644 KiB

Open AccessArticle

Linear Project-Scheduling Optimization Considering a Reverse Construction Scenario

by Ze Yu, Chuxin Wang, Yuanyuan Zhao, Zhiyuan Hu and Yuanjie Tang

Appl. Sci. 2023, 13(16), 9407; https://doi.org/10.3390/app13169407 - 18 Aug 2023

Cited by 1 | Viewed by 830

Abstract

The linear scheduling method (LSM) for optimization in linear projects has been the focus of numerous academic studies over the years. However, research on incorporating reverse construction activities and other practical scenarios, such as flexible activity–section–crew assignment demands, in linear project-scheduling optimization remains [...] Read more.

The linear scheduling method (LSM) for optimization in linear projects has been the focus of numerous academic studies over the years. However, research on incorporating reverse construction activities and other practical scenarios, such as flexible activity–section–crew assignment demands, in linear project-scheduling optimization remains insufficient. This has further spurred research on practical scenario-based linear project-scheduling optimization. We performed an analysis of a description method system within the LSM framework, outlining the spatiotemporal logical relationship in scenarios involving reverse activities. A scheduling optimization model incorporating a flexible constraint system, capable of handling multisection–multicrew, multicrew–multimode, and multicrew–multiconstruction direction scenarios is developed to enhance the practicability of linear project-scheduling optimization. Additionally, an advanced grey wolf optimization (GWO) algorithm is devised and validated through a real-world case study. The case study provides insights into the impact of reverse construction activities on the linear project-scheduling problem, specifically in the dimension of project duration. Full article

(This article belongs to the Special Issue Railway Infrastructures Engineering: Latest Advances and Prospects)

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19 pages, 8197 KiB

Open AccessArticle

Structural Performance of Prefabricated Composite Girders for Railway Bridges along with Girder-to-Deck Interface Connections for Mechanical Injection

by Hung Thanh Diep, Jiho Moon and Byung H. Choi

Appl. Sci. 2023, 13(11), 6686; https://doi.org/10.3390/app13116686 - 31 May 2023

Cited by 2 | Viewed by 1558

Abstract

Recently, to resolve a growing need for durable and resilient railway bridge construction/reconstruction systems, a great amount of research has been carried out in many countries. As a part of such studies, prefabricated composite girders with an innovative girder-to-deck connection have been proposed [...] Read more.

Recently, to resolve a growing need for durable and resilient railway bridge construction/reconstruction systems, a great amount of research has been carried out in many countries. As a part of such studies, prefabricated composite girders with an innovative girder-to-deck connection have been proposed that facilitate construction by eliminating interference during on-site processes. In this study, a railway bridge prototype of prefabricated composite girders with girder-to-deck connections was designed to facilitate future application enhancement of off-site construction. Then, prefabricated composite girders were developed by deploying different girder-to-deck connections through geometric detailing of reinforcement, headed stud connectors, and precast decks. Based on the calculation theory of interface shear transfer, the detailed design of different girder-to-deck connections was carried out, in particular the reinforcement spacing. Furthermore, finite element analysis of prefabricated composite girders was conducted to determine the flexural moment strength of prefabricated composite girders. Parametric studies were carried out to consider the factors affecting the detailed design of the connection, ensuring that the connection is correctly designed, thereby ensuring the structural performance of prefabricated composite girders. From the results, conclusions were drawn. The developed cases satisfied the interface shear criteria according to both conventional and plastic approaches. There was no significant difference in flexural moment strength between the developed cases since all cases were designed with the full shear connection. In all cases, the flexural performance was ensured and can be used for railway bridges. The most optimum case of prefabricated composite girders is selected in specific design situations. Full article

(This article belongs to the Special Issue Railway Infrastructures Engineering: Latest Advances and Prospects)

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15 pages, 8155 KiB

Open AccessArticle

Simplified Dynamic FEA Simulation for Post-Derailment Train-Behaviour Estimation through the Enhanced Input of Wheel–Ballast Friction Interactions

by Jaehoon Lim and Jungsik Kong

Appl. Sci. 2023, 13(11), 6499; https://doi.org/10.3390/app13116499 - 26 May 2023

Cited by 4 | Viewed by 1119

Abstract

With the increasing demands for railway transportation, railway networks have expanded, leading to higher operating frequencies and speeds. However, this has also, in turn, increased the technical complexity of railway transportation systems. Derailment accidents, which occur frequently and have complex outcomes, are primary [...] Read more.

With the increasing demands for railway transportation, railway networks have expanded, leading to higher operating frequencies and speeds. However, this has also, in turn, increased the technical complexity of railway transportation systems. Derailment accidents, which occur frequently and have complex outcomes, are primary concerns in such systems. Particularly, derailments cause significant damage to adjacent areas, increasing their severity compared to other railway accidents. However, a majority of research on derailment accidents has focused on preventing or simulating specific situations, whereas the analysis of post-derailment train behaviour still requires improvements. This study aimed to predict post-derailment train behaviour using finite element analysis simulations of simplified train and track models using Korea as a case study; the key factors considered were the operating speed, derailment angle, and ground friction coefficient. Various accident cases in Korea were reviewed and compared with simulated results to verify the proposed model. Full article

(This article belongs to the Special Issue Railway Infrastructures Engineering: Latest Advances and Prospects)

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19 pages, 10863 KiB

Open AccessArticle

Influence of Stray Current on Fastening System Components in Urban Railway Tracks

by Katarina Vranešić, Stjepan Lakušić and Marijana Serdar

Appl. Sci. 2023, 13(9), 5757; https://doi.org/10.3390/app13095757 - 6 May 2023

Cited by 3 | Viewed by 2017

Abstract

Urban railway tracks are the primary modes of transportation in many cities worldwide. Track vehicles mostly use DC from overhead lines, and rails are used as return conductors. Because it is challenging to fully insulate the rail and ensure high rail-to-ground resistance, current [...] Read more.

Urban railway tracks are the primary modes of transportation in many cities worldwide. Track vehicles mostly use DC from overhead lines, and rails are used as return conductors. Because it is challenging to fully insulate the rail and ensure high rail-to-ground resistance, current leaks from the rail to the lower part of the track. This current is referred to as stray current. To determine the detrimental effects of stray current on the rail and fastening system components, we performed a laboratory simulation of the stray current on four real-scale samples of the entire rail with all fastening components. The difference among these four samples was the type of fastening system used. Tests were performed under dry condition and at different water levels. After testing, the samples were visually inspected. Under dry conditions, corrosion occurred on the elements in contact with the concrete, and under immersed conditions, the current leaked from all components of the fastening system directly into the water, causing harmful local deterioration. The characteristics of the fastening systems are defined to satisfy other parameters, but not to prevent stray currents and ensure high rail-to-ground resistance. The aim of this study was to demonstrate the effects of stray current on the rail and fastening system and to prove the importance of providing adequate drainage of the track and using a fastening system that is insulated and does not allow the current to leak from the rail. Full article

(This article belongs to the Special Issue Railway Infrastructures Engineering: Latest Advances and Prospects)

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14 pages, 6399 KiB

Open AccessArticle

Study on the Reducing Measures to Reduce the Influence of Culvert Extension on Existing Lines in Loess Regions

by Wenhui Zhao, Ke Zhang, Feng Han and Dingshun Wang

Appl. Sci. 2023, 13(7), 4138; https://doi.org/10.3390/app13074138 - 24 Mar 2023

Viewed by 1124

Abstract

Due to the many constraint conditions, construction difficulties, and high control standards, and the impact of new line construction on existing lines, the construction of culvert extensions in widened sections of loess areas has become a form of control in railway construction projects. [...] Read more.

Due to the many constraint conditions, construction difficulties, and high control standards, and the impact of new line construction on existing lines, the construction of culvert extensions in widened sections of loess areas has become a form of control in railway construction projects. This work analyzes the technical difficulties of culvert extension construction schemes based on a practical engineering case. A scheme to provide culvert protection against slight disturbances is determined, and the construction schemes of the culvert extension structure and transition section filling are optimized. The rationality of culvert extension control measures and the influence of construction on the existing line are then studied based on the monitoring data for each stage. The results show that the implementation of the slight disturbance culvert protection has little influence on the existing line, and has the greatest influence during steel sheet pile construction (<0.5 mm). We symmetrically construct the culvert extension structures (transverse) and transition section filling (longitudinal and transverse) to effectively reduce the influence of differences in the deformation value between the two sides of the existing line at the same level as the existing line. The deformation of the upper side of the culvert fluctuates with the construction of the composite foundation and shows an overall upward trend, while the deformation increases first and then decreases in the transition section, and the deformation of the upper side of the culvert is larger than that of the transition section. The level gauge deformation of each side decreases abruptly at the filling stage of the bottom plate, side plate, top plate, and splayed wall. The settlement value of the level gauge of each station increases nonlinearly with the increase in the filling height of the transition section, and the settlement variation value of the transition section at each filling stage is higher than that of the upper side of the culvert. Full article

(This article belongs to the Special Issue Railway Infrastructures Engineering: Latest Advances and Prospects)

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14 pages, 4652 KiB

Open AccessArticle

A Methodology Linking Tamping Processes and Railway Track Behaviour

by Stefan Offenbacher, Christian Koczwara, Matthias Landgraf and Stefan Marschnig

Appl. Sci. 2023, 13(4), 2137; https://doi.org/10.3390/app13042137 - 7 Feb 2023

Cited by 1 | Viewed by 2299

Abstract

Today’s railway transport is built upon high-performance infrastructure. Cost-effective yet sustainable infrastructure presumes tracks with a precise and durable geometry. At ballasted tracks, the geometry is created and restored through tamping machines, which position the track panel and compact the ballast beneath the [...] Read more.

Today’s railway transport is built upon high-performance infrastructure. Cost-effective yet sustainable infrastructure presumes tracks with a precise and durable geometry. At ballasted tracks, the geometry is created and restored through tamping machines, which position the track panel and compact the ballast beneath the sleepers. It is commonly agreed that the ballast compaction plays an important role in the long-term stability of the track. Yet, there is no method available which allows a direct correlation between the compactness of the ballast and the stability of the track geometry. Available studies either model track behaviour without considering the bedding, or analyse ballast compactness locally while disregarding its influence on the track geometry. This paper presents a new methodology which establishes a relation between these two topics—ballast compaction during tamping and subsequent track behaviour. A state-of-the-art tamping machine has been equipped with an experimental measurement setup, constantly recording relevant data during every tamping process. These data can be used to derive an indication for the achieved compaction under every sleeper. Utilising the tamping machine’s internal measuring system for track geometry documentation, every tamping process (every sleeper) is assigned to the precise position along the track. The data set is merged and synchronised with regular track geometry measurements of the infrastructure manager. The result is a comprehensive data set which allows precise analyses between tamping machine measurements and track behaviour. This data set provides the foundation for future research, aiming towards a better understanding of the tamping process and its influence on the quality and durability of the established track geometry. Full article

(This article belongs to the Special Issue Railway Infrastructures Engineering: Latest Advances and Prospects)

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11 pages, 10873 KiB

Open AccessArticle

Comparison of Fatigue Performances Based on Shape Change of Rail Fastening Spring

by Xiao-Jun Fang, Yeun-Chul Park, Jong-Wan Hu and Hyoung-Bo Sim

Appl. Sci. 2023, 13(3), 1770; https://doi.org/10.3390/app13031770 - 30 Jan 2023

Viewed by 1289

Abstract

The fastening spring of a rail fastening system serves as an important connection in transferring the train load to the sleeper via rails on railway tracks. During initial fastening, a large tensile stress exceeding the yield stress can occur in the fastening spring [...] Read more.

The fastening spring of a rail fastening system serves as an important connection in transferring the train load to the sleeper via rails on railway tracks. During initial fastening, a large tensile stress exceeding the yield stress can occur in the fastening spring structure, making it vulnerable to fatigue owing to stress fluctuations during train use. The damage caused by fatigue in the fastening springs have been reported for rail fastening systems on several domestic and international routes; however, research on this topic is limited. This study evaluates the fatigue performance of a fastening spring, SPS9 spring steel, developed in Korea based on shape change by performing a sensitivity analysis of various factors, including the heights at the end of the fastening spring and the spring arm, overall lateral width, and the diameter of the cross section of the fastening spring. The modified Goodman fatigue diagram was applied based on the tensile stress on initial fastening and the constant stress range due to a rail vertical displacement caused by train use through finite element analysis. The fatigue analysis showed that the lateral width and diameter factors of the fastening spring are found to be important variables for fatigue performance. Moreover, as the width and diameter increase, the fatigue performance improves significantly. The fatigue safety margin increased from 64% to 82% when the width increased from −20% to +20%, and increased from 54% to 81% with the diameter increase from 13 mm to 18 mm. Full article

(This article belongs to the Special Issue Railway Infrastructures Engineering: Latest Advances and Prospects)

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Review

Jump to: Research

29 pages, 6685 KiB

Open AccessReview

Drive-by Methodologies Applied to Railway Infrastructure Subsystems: A Literature Review—Part II: Track and Vehicle

by Cássio Bragança, Edson F. Souza, Diogo Ribeiro, Andreia Meixedo, Túlio N. Bittencourt and Hermes Carvalho

Appl. Sci. 2023, 13(12), 6982; https://doi.org/10.3390/app13126982 - 9 Jun 2023

Cited by 3 | Viewed by 1802

Abstract

Railways are one of the most important means of transportation, allowing people and goods to move quickly, environmentally beneficially, and efficiently over long distances. To ensure safe and reliable operations, regular condition-based assessments of trains and track are of paramount importance. Drive-by methodologies, [...] Read more.

Railways are one of the most important means of transportation, allowing people and goods to move quickly, environmentally beneficially, and efficiently over long distances. To ensure safe and reliable operations, regular condition-based assessments of trains and track are of paramount importance. Drive-by methodologies, which utilize data collected by onboard monitoring systems as the vehicle travels over the track, have gained popularity as an economically viable strategy for monitoring extensive track networks as well as vehicles traveling on them. This paper presents a critical review of these methodologies applied to railway tracks and vehicles. It assesses research on track irregularities, rail conditions, and the condition of rail supporting elements, highlighting important early developments and recent papers that provide insights into future practical applications. Additionally, the paper explores works related to global vehicle condition evaluation, focusing on the identification of suspension and wheelset element damage and also discussing challenges towards commercial application. The findings suggest that drive-by methodologies have several promising future applications. These include track maintenance optimization, proactive fault detection, predictive maintenance, track performance evaluation, vehicle health monitoring, and data-driven decision-making. By leveraging drive-by assessments, railway operators can optimize maintenance efforts, detect faults early, predict remaining component life, evaluate track performance, monitor vehicle health, and make informed decisions based on data analysis. Finally, a comprehensive conclusion summarizes the achievements thus far and provides perspectives for forthcoming developments. The future practical applications of drive-by methodologies discussed in this review have the potential to revolutionize railway track and vehicle assessments, leading to safer and more efficient railway operations in the days to come. Full article

(This article belongs to the Special Issue Railway Infrastructures Engineering: Latest Advances and Prospects)

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31 pages, 6178 KiB

Open AccessReview

Drive-by Methodologies Applied to Railway Infrastructure Subsystems: A Literature Review—Part I: Bridges and Viaducts

by Edson F. Souza, Cássio Bragança, Andreia Meixedo, Diogo Ribeiro, Túlio N. Bittencourt and Hermes Carvalho

Appl. Sci. 2023, 13(12), 6940; https://doi.org/10.3390/app13126940 - 8 Jun 2023

Cited by 4 | Viewed by 1642

Abstract

Bridges and viaducts are critical components of railway transport infrastructures, providing safe and efficient means for trains to cross over natural barriers such as rivers and valleys. Ensuring the continuous safe operation of these structures is therefore essential to avoid disastrous economic consequences [...] Read more.

Bridges and viaducts are critical components of railway transport infrastructures, providing safe and efficient means for trains to cross over natural barriers such as rivers and valleys. Ensuring the continuous safe operation of these structures is therefore essential to avoid disastrous economic consequences and even human losses. Drive-by methodologies have emerged as a potential and cost-effective monitoring solution for accurately and prematurely detecting damage based on instrumented vehicles while minimizing disruptions to train operations. This paper presents a critical review of drive-by methodologies applied to bridges and viaducts. Firstly, the premises of the method are briefly reviewed, and the potential applications are discussed. In sequence, several works involving the use of drive-by methodologies for modal characteristic extraction are presented, encompassing the most important methodologies developed over time as well as recent advancements in the field. Finally, the problem of damage identification is discussed—both in relation to modal and non-modal parameter-based techniques considering the most promising features and the current advancements in the development of methodologies for damage detection based on machine learning algorithms. A comprehensive conclusion is presented at the end of the article, summarizing the achievements and providing perspectives for future developments. By critically assessing the application of drive-by methodologies to bridges and viaducts, this paper contributes to the advancement of knowledge in this crucial area, emphasizing the significance of continuous monitoring for ensuring the integrity and safety of these vital transport infrastructures. Full article

(This article belongs to the Special Issue Railway Infrastructures Engineering: Latest Advances and Prospects)

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