Railway Line Research Articles

Upgrade of a conventional railway line regarding energy efficiency

Upgrade of a conventional railway line regarding energy efficiency

Evaluasi Optimalisasi Cash Flow Pada Proyek Multiyears Dengan Penyesuaian Perubahan Waktu Pelaksanaan (Studi Kasus Proyek Pembangunan Jalur Kereta Api Lintas Makassar-Pare pare)

The construction of the Trans-Sulawesi railway line is a railway network built to reach important areas on the island of Sulawesi. In general, the implementation of construction projects is limited by a certain time with limited resources to complete a given job, but due to the unavailability of land when the Work Start Order is issued, it causes a time addendum twice without any cost escalation. The purpose of this research is to get the optimal cash flow that can be obtained by contractors based on changes in implementation time and get the right strategy that can be applied in the future so that no more Addendum changes in implementation time can harm the implementing contractor. Data collection includes primary data by interviewing 25 respondents representing 155 populations consisting of 15 work units, 10 supervisory consultants, 25 implementing contractors and 105 land owners. Secondary data collection was carried out by requesting the necessary data from the implementing contractor. Cash Flow optimization evaluation is carried out by calculating 2 cash flow simulations, namely: Simulation 1 (823 days based on addendum 1), simulation 2 (1063 days / based on addendum 2). Determination of the right strategy to avoid addendum changes in implementation time is done using SWOT Analysis. Calculation of both simulations obtained results: In Simulation 1 (823 days) the acceleration of the implementer

Prevent sand accumulation under the windbreak wall along railways in strong wind areas

The Lanxin High-Speed Railway is the world's first high-speed railway to pass through a strong wind region. Many windbreaks were installed along the railway line to reduce the adverse effects of wind on passing trains. The windbreak wall blocks strong wind, reduces the velocity of sand particles, and minimizes sand accumulation on the track. This paper proposes a solution based on fluid mechanics and the two-phase flow of wind and sand to reduce sand accumulation on railway tracks. Wind tunnel experiments and numerical simulations are conducted for three scenarios: the existing windbreak wall and a 45-degree inclined board installed at the wall's top or the leeward side. The results show that the sand accumulation and wind speed are higher on the windward side. The largest sand accumulation occurs when the 45-degree inclined plate is installed at the top and the wind speed is 15 m/s. The sand accumulation on the track is the lowest, the negative wind speed is the highest when the 45-degree inclined plate is located at the top on the windward side, and the wind speed is 30 m/s. Sand accumulation on the track can be minimized by taking advantage of the highly turbulent area. The sand particle size on the actual track is lower than the average sand particle size at the start of the sand bed. Our results can be used to optimize measures to prevent or minimize sand accumulation in railway lines and towns in windy areas and mitigate desertification.

Dynamic changes and influential factors of blowouts in a desert artificial ecosystem at the southeastern margin of Tengger Desert in China.

The wind-blown sand protection system in the Shapotou section of the Baotou-Lanzhou Railway is a representative artificial ecosystem in a desert region. Over the past 70 years, this system has transformed mobile dunes into fixed dunes through vegetation succession, relying solely on natural rainfall without additional irrigation. However, ecosystem sustainability has been endangered by the emergence of numerous blowouts. Therefore, understanding the status and developmental trends of these blowouts is crucial for maintaining the system and ensuring railway safety. In this study, we quantitatively analyzed the number, spatial pattern, and evolution process of blowouts using a landscape pattern index and Spatial-Temporal Analysis of Moving Polygons (STAMP) model with remote sensing images from 2009 to 2022. Currently, blowout areas account for 1.57% of the total area with a clustered distribution. The number of blowouts increased significantly from 308 to 463 between 2009 and 2022 and increased with increasing distance from the railway line. Various evolutionary events have occurred among the blowouts, with peak frequencies in the generation and disappearance events observed by 2022. The average growth rate of blowouts was 7.32% in areas with less than 40 years of sand fixation but less than 1% in areas with more than 40 years, and mid-sized blowouts predominated the overall protection system. There was little difference between the blowout wind-erosion area and the fixed area in the natural environment. However, human activities can accelerate the evolution of blowouts, leading to more frequent contraction and expansion events and significantly increasing the area of wind erosion.

Enhancing safety in adapting personal vehicles for disused railway lines: Key rail texture parameters influencing Tire/Rail skid resistance

Enhancing safety in adapting personal vehicles for disused railway lines: Key rail texture parameters influencing Tire/Rail skid resistance

Backstepping controller for speed loop of permanent magnet synchronous motors integrated with a time-varying disturbance load observer for Metro Nhon-Hanoi Station

Urban rail systems offer the substantial potential for reducing environmental pollution, alleviating traffic congestion, ensuring safety, and maintaining punctuality. Nevertheless, the operation of urban rail demands substantial electrical energy, and saving energy solutions are crucial to exploiting the full advantages of electric trains. This paper proposes the replacement of traditional traction motors with permanent magnet synchronous motors (PMSMs) due to their superior efficiency, reduced power losses, and compact size compared to direct current (DC) motors or other asynchronous three-phase motors with equivalent power, developing a backstepping controller for the speed loop coupled with a load observer-time-varying disturbance (TVD). The simulation results were conducted in MATLAB/Simulink with parameters collected from the Nhon-Hanoi urban railway line, Vietnam, verifying the proposed algorithms' correctness and effectiveness.

Study on semi-active damping control strategies to improve dynamic behavior of high-speed trains subject to strong crosswinds

The aerodynamic loads on high-speed trains (HSTs) increase as the running speed increases. Particularly, strong crosswinds can significantly increase these loads and generate a safety risk to trains. This paper focuses on the application of semi-active control strategies based on secondary lateral suspension for HST operating in crosswinds, aiming to enhance the running safety of HST. First, a vehicle nonlinear dynamics model with 50 degrees of freedom (DOFs) is established. The aerodynamic loads caused by crosswinds are simulated using Simiu wind spectra, and the track irregularities are acquired through field tests of the high-speed railway line. Second, a semi-active control model is set up using Matlab/Simulink to replace the secondary lateral damper, and the co-simulation for vehicle dynamics and semi-active control is undertaken. Then, the vibration characteristic analysis of the vehicle system caused by aerodynamic loads under crosswind conditions is conducted in both time and frequency domains, while a conventional semi-active control strategy is employed to attenuate the vibrations. Moreover, a single coefficient mixed skyhook and groundhook control strategy (SMSG) regulated by a single mixing coefficient β, and mixed skyhook and acceleration driven damper control strategy (MSA) is proposed. The simulation results demonstrate that the proposed mixed skyhook and groundhook control strategy not only enhances the running safety of the trains in crosswind environments by adjusting the mixing coefficients but also improves ride performance compared to passive suspensions. While the suggested mixed skyhook and ADD control strategy can apparently reduce the vibration of the carbody.

Seismic fragility, loss, and resiliency of old railway masonry arch bridges under near-field ground motion

ABSTRACT Iran’s historic railway arch bridges, many over a century old, face seismic risks due to their original design neglecting lateral loads. As they are often situated in seismically active zones near fault lines, understanding their seismic vulnerability is crucial. The goal of this study is to assess the seismic fragility and loss estimation of such bridges under various seismic events. To this end, the seismic performance of two masonry arch bridges, specifically a bridge with two long spans, named 2LS20, and a bridge featuring five small spans, named 5SS06, along the old Tehran-Qom railway line, is assessed under a set of 28 near-field and 22 far-fault earthquake records. Throughout the nonlinear incremental dynamic analysis, seismic fragility analyses were performed to ascertain the likelihood of damage across distinct limit states for each bridge model under the action of near and far-fault ground motions. Subsequently, throughout the resiliency analysis, the recovery process was simulated to assess the progress of bridge functionality with time. Moreover, seismic loss analyses were conducted to assess the comparative economic viability of the studied models. The results indicate the 5SS06 bridge for lower vulnerability and repair costs with near-fault motions posing higher risks, particularly for extreme damage conditions. Resilience varies significantly based on recovery models, with the 5SS06 bridge showing more effortless recovery under far-fault motions and higher resilience factors under near-fault records. Additionally, predictive equations were proposed for managing seismic risks in similar bridge infrastructures, particularly in Iran’s railway network, aiding resilience and risk mitigation planning.

Maintenance Management In Handling The Problem of Rail Damage Affecting Railway Travel Safety (Wonokromo-Sidoarjo Route)

Regarding the number of trains that have accidents, one of them is due to damaged rails among 4 other causes, so that it has an impact on the delay and safety of the train journey itself. The purpose of this study is as an input related to the maintenance management system, especially in terms of handling problems of damage to railway infrastructure, in this case rail lines that require maintenance, especially regarding human resources who handle them, so that appropriate solutions can be obtained in short-term or long-term solutions for the comfort and safety of train travel. This study uses a mix method, and when identification is carried out, problems are found on the railway, namely the number of damages where after analysis, the results are a number of maintenance equipment that is still lacking, as well as the number of logistics or spare parts. And after being evaluated, it was found that some damage to the components of the Wonokromo – Sidoarjo cross rail road was caused by the cross load received by the cross of 11,543,796 tons/year, so that when it is associated with PM 60 of 2012 concerning Technical Requirements for Railway Lines, the Wonokromo-Sidoarjo cross should no longer be included in road class III but class II, so that maintenance management is needed in the maintenance of railway infrastructure which should be further improved, especially in terms of fulfilling certified human resources.

An enhanced YOLOv8n-based method for detecting color steel plate conditions along railway lines using drone inspection images

Abstract The color steel houses along railway lines often suffer from improper installation, aging, and deformation. Under strong wind conditions, the color steel roofing panels are prone to being blown onto railway tracks and facilities, posing a threat to train operation safety and potentially causing serious accidents. To address these issues, this paper proposes a method for detecting the condition of color steel panels along railway lines based on drone inspection images. The proposed method is built upon the You Only Look Once (YOLO) series algorithm framework, with specific improvements targeting the detection of small-sized color steel houses and those with similar characteristics that are difficult to classify in images. Firstly, a backbone network based on FasterNet is established, leveraging the characteristics of inverted residual blocks in the FasterNet module to optimize and enhance the feature extraction capability of the original network for small-sized color steel panels while reducing computational redundancy and memory access costs. Secondly, an Attention-based Intra-scale Feature Interaction (AIFI) module is introduced after the backbone network to enhance the model’s ability to focus on fine-grained information by facilitating interaction at the scale of high-level features. Finally, a new CSP Bottleneck with 2 Convolutions- Dilation-wise Residual (C2F-DWR) module is designed to optimize the small object detection capability of the C2F module in the neck network. This module uses a two-step approach to capture multi-scale information, which reduces the model’s parameter size while comprehensively improving the detection performance of the algorithm. The results show that the improved algorithm achieves a 4.9% increase in detection accuracy, a 3.2% increase in recall rate, and a 3.3% increase in mean Average Precision (mAP) compared to YOLOv8n (a lightweight variant of the YOLOv8 series). YOLOv8n has a smaller network structure and lower computational overhead, making it suitable for resource-constrained environments. These results demonstrate that the proposed method significantly improves the detection of small-sized color steel houses and the classification of objects with similar characteristics.

Post-monitoring evolution: mathematical model for neutral temperature development in continuous welded rail

ABSTRACT The long-term development of neutral temperature in continuous welded rail (CWR) was investigated using measurement systems equipped with self-compensated strain gauges in quarter bridge configuration. Field measurements on railway lines were conducted over a two-year period following the installation of the CWR. In tracks with lower traffic intensity and stiffness, the CWR neutral temperature could easily reach 40°C during summer but dropped below 30°C in winter. In contrast, in stiffer tracks with higher traffic intensity and heavier loads, the long-term deviation of the CWR neutral temperature remained within significantly narrower limits (closer to the CWR installation temperature – 23°C). Regardless of track stiffness or traffic intensity, the trends in CWR neutral temperature development were found to be similar for the left and right rails within the same profile of monitored section. The proposed machine learning (ML)-enhanced, and regression-based mathematical models accurately represent the long-term development of neutral temperature in CWR.

A Capacity-Utilization-Oriented Stop Planning Approach for High-Speed Railway Network with Stop Distribution Balance

Stop planning is aimed to provide proper services for passenger demand, but diverse stop patterns lead to differences in stop density and travel speeds, impacting the utilization of line capacity. This paper incorporates capacity utilization into stop planning in the strategic line planning stage to trade off the matching between supply and demand and the stop distribution balance among trains. A bi-level programming model is established to formulate the Stackelberg game relation between supply and demand, where the stop distribution imbalance and the passenger travel inefficiency are measured. An adaptive hybrid solving algorithm combined with Genetic Algorithm and Simulated Annealing Algorithm is proposed, with several adaptive operations according to the problem characteristics and optimization degree to improve searching efficiency. A case study on the local network of Beijing–Shanghai High-speed Railway Line demonstrates that the proposed approach can not only mitigate the stop distribution imbalance, but also improve the travel efficiency of passengers, indicating that it can benefit the simultaneous improvement of capacity utilization and service level.

Soil environmental monitoring of repurposed railway line operated for 75 years: case study in Northeast Poland

Soil environmental monitoring of repurposed railway line operated for 75 years: case study in Northeast Poland

Analysis of Landfill Site Suitability for Solid Waste Disposal in the Ranchi District of Jharkhand, India Using Analytical Hierarchy Process and Geo-Spatial Techniques

ABSTRACT The selection of an appropriate landfill site is a complex issue due to the involvement of numerous criteria and constraints. A non-engineered and unsuitable site can harm the environment, society and economy of an area. This paper focuses on the application of Geographic Information System (GIS) and Analytical Hierarchy Process (AHP), a multi-criteria decisionmaking technique, to determine suitable landfill sites. A total of nine parameters have been used namely; groundwater depth, slope, geology, existing landfill site, drainage density, road network, land use and land cover (LULC), railway lines and airport. The weights were calculated using AHP. A landfill site suitability map was generated with 5 classified areas namely; most unsuitable (0.07%), unsuitable (5.42%), less suitable (23.94%), moderately suitable (58.24%) and most suitable (12.38%). The areas identified in the study can be used by policymakers in both urban as well as rural developmental planning and waste management. Using the patches of land from the landfill suitability map, a decentralised community-based landfill model can also be adopted to minimize and possibly eliminate the need for large landfill sites.

Analysis of Landfill Site Suitability for Solid Waste Disposal in the Ranchi District of Jharkhand, India Using Analytical Hierarchy Process and Geo-Spatial Techniques

ABSTRACT The selection of an appropriate landfill site is a complex issue due to the involvement of numerous criteria and constraints. A non-engineered and unsuitable site can harm the environment, society and economy of an area. This paper focuses on the application of Geographic Information System (GIS) and Analytical Hierarchy Process (AHP), a multi-criteria decisionmaking technique, to determine suitable landfill sites. A total of nine parameters have been used namely; groundwater depth, slope, geology, existing landfill site, drainage density, road network, land use and land cover (LULC), railway lines and airport. The weights were calculated using AHP. A landfill site suitability map was generated with 5 classified areas namely; most unsuitable (0.07%), unsuitable (5.42%), less suitable (23.94%), moderately suitable (58.24%) and most suitable (12.38%). The areas identified in the study can be used by policymakers in both urban as well as rural developmental planning and waste management. Using the patches of land from the landfill suitability map, a decentralised community-based landfill model can also be adopted to minimize and possibly eliminate the need for large landfill sites.

Leader-Follower Heterogeneous Surveillance System Oriented to High-Speed Railway Lines Security

Leader-Follower Heterogeneous Surveillance System Oriented to High-Speed Railway Lines Security

Alleviating tunnel aerodynamics through hybrid suction & blowing techniques applied to train nose sections

Alleviating tunnel aerodynamics through hybrid suction & blowing techniques applied to train nose sections

A side-sampling based Linformer model for landslide susceptibility assessment: a case study of the railways in China

The improvement of landslide susceptibility assessment is a long-standing problem in hazard mitigation work, wherein previous studies have proposed various training models. However, the ratio of positive to negative samples and the selection of non-landslide samples have been shown to significantly influence results. These research directions have traditionally been focal points, while datasets are often overlooked, serving merely as auxiliary tools to support the validation process. Hence, this study proposes an approach to enhance datasets through the introduction of the side-sampling method. This technique focuses on individual research cells, conducting feature sampling training on fixed regions of length M, thereby enabling more precise identification of geographical clustering characteristics. Using evaluation metrics such as accuracy, precision, recall, F1 score, and ROC curve, this study conducts a comparative analysis between the side-sampling method and traditional sampling methods, using three distinct railway lines in China as the study areas. Results show substantial improvements beyond several exceptions: accuracy (+7.68%), precision (+7.19%), recall (+13.48%), F1 score (+9.92%), and ROC (+6.22%). The results demonstrate a significant overall improvement in the performance of the trained models based on the side-sampling method, providing a positive insight into mitigating landslide hazards along railways from the dataset perspective.

Railway transport system modelling approach for robustness analysis

The article presents an approach to train traffic modelling that allows for the analysis of how railway networks respond to various disturbances, including increased traffic and disturbance events. It discusses different methods of reconfiguration actions in key points of the railway network, which helps reduce delay propagation in the transport system. The 1st part covers building simulation models, which include defining infrastructure, setting train routes, configuring rolling stock, and disturbance scenarios, enabling the analysis of various disruptive events. The simulations allow for testing disturbance scenarios with minimal downtime risk without interfering with the real-world environment. The study results identified key system parameters generating the largest delays, such as platform availability, signaling, and the number of block sections. Probability density distributions for event intervals and durations were analyzed. The Kolmogorov–Smirnov test was used to confirm the fit of empirical distributions with theoretical ones, which were then implemented in the model of railway line No 271, running from Wrocław to Żmigród (Poland). As part of the reconfiguration of this railway line, new platforms were added, the time required for route setting was reduced, and the number of block sections was increased. These actions significantly reduced average delays, improved line capacity, and enhanced the robustness of the railway transport system against disturbances. The reconfiguration effectively reduced delays in areas causing significant time exceedances above 359 s, which was recognized in the Polish railway network as critical.

PELAKSANAAN GANTI RUGI SENGKETA TANAH DALAM PROYEK INFRASTRUKTUR PEMBANGUNAN JALUR KERETA CEPAT JAKARTA-BANDUNG

The purpose of this research is to provide an explanation of the implementation of compensation in infrastructure projects. The research methods used are normative and empirical juridical legal research methods. Land is a basic human need that is very important in human life. Indonesia's population growth is increasing rapidly, so there is little land available to meet the needs of the community. However, the government must carry out development to provide adequate infrastructure for the community to better support their lives. In carrying out development, especially for the public interest, it is often necessary to use land from the community. The community land can be used for development purposes through the process of land acquisition for public interest. During the land acquisition process, the most important thing is the agreement between the agency that needs the land and the landowning community to determine the form and amount of compensation. Compensation is a proper and fair replacement to the rightful party in the land acquisition process. Land acquisition is very important for infrastructure development, one of which is the construction of a railway line. The government has the legitimacy to take over land owned by individuals or legal entities for the construction of the Jakarta-Bandung High Speed Railway. The construction of the Jakarta-Bandung High Speed Railway is a public project that requires a land acquisition process. The land acquisition process can run smoothly with appropriate compensation.