The granular sub-ballast layer commonly used in the construction of modern railway tracks, but its use involves a significant consumption of natural aggregates, which, moreover, must meet certain ...requirements that are sometimes unavailable. Therefore, the possibility of using recycled aggregates arises to promote sustainable development. In this context, this research focuses on assessing the feasibility of using RAP (Reclaimed Asphalt Pavement) as a sub-ballast layer in railway tracks, these recycled materials can contribute to increased load-bearing capacity and waterproofing of the lower layers due to the presence of adhered bitumen, studying the optimal application process to achieve a layer with high mechanical performance. It presents a laboratory investigation on the influence of different design factors on the mechanical performance of the layer, evaluating the effects of RAP characteristics, and the impact of the compaction procedure. Although these recycled materials primarily presented challenges in terms of size, particle distribution, and strength, which differ from the aggregates commonly used in similar high-demand layers, laboratory tests simulating expected service conditions for these materials in railway tracks have shown the viability and suitability of using recycled asphalt materials to achieve more sustainable railway tracks. Under compaction conditions at temperatures commonly achieved in construction (above 40 ºC) and considering its particle size distribution, it is possible to create a layer with high performance in terms of strength and durability.
•RAP was studied to be used as granular subballast for railway track.•Influence of RAP type, compaction temperature and particle size were evaluated.•Full-scale track box tests were conducted to simulate real conditions scenario.•RAP showed appropriate behavior for application as sub-ballast in railway tracks.
Many infrastructure managers have the goal to increase the capacity of their railway infrastructure due to an increasing demand. While methods for performance calculations of railway line ...infrastructure are already well established, the determination of railway junction capacity remains a challenge. This work utilizes the concept of queueing theory to develop a method for the capacity calculation of railway junctions, solely depending on their infrastructure layout along with arrival and service rates. The implementation of the introduced approach is based on probabilistic model-checking. It can be used to decide which infrastructure layout to build, i.e. whether an overpass for the analysed railway junction is needed. The developed method addresses the need for fast and reliable timetable-independent railway junction capacity evaluation, catering specifically to the long-term strategic planning of junction infrastructure.
•Timetable independent capacity analysis of railway junctions.•Formulation as a queueing system utilizing Continuous-Time Markov Chains.•Application of state-of-the-art probabilistic model-checking to estimate performance indicators.•Decision support for infrastructure managers when planning required infrastructure layouts.•Comparison with classical methods determining the capacity occupation of railway infrastructure.
This paper is focused on the data description of the railway infrastructure. Its aim is to present the possibilities of constructing of linear elements representing tracks in 2D and their subsequent ...transformation into 3D using the parametric description of horizontal and vertical curves. The transformation is based on determining the spatial coordinates of the newly emerging 3D linear elements. This process is supposed to be implemented in such a graphical editor environment that allows the relevant data to be transferred to the the database based on the Multipurpose Railway Infrastructure Model. With the use of this data, it is possible to perform, among other things, the visualization of the railway infrastructure.
Safety of transportation networks is of utmost importance for our society. With the emergency of digitalization, the railway sector is accelerating the automation in inventory and inspection ...procedures. Mobile mapping systems allow capturing three-dimensional point clouds of the infrastructure in short periods of time. In this paper, a deep learning methodology for semantic segmentation of railway infrastructures is presented. The methodology segments both linear and punctual elements from railway infrastructure, and it is tested in four scenarios: i) 90 km-long railway; ii) 2 km-long low-quality point clouds; iii) 400 m-long high-quality point clouds; iv) 1.4 km-long railway recoded with aerial mapping system. The longest one is used for training and testing, obtaining mean accuracy greater than 90%. The other scenarios are used only for testing, and qualitative results are discussed, proving that the method can be applied to new scenarios that significantly differ in terms of data quality and resolution.
•Railway point clouds automatic semantic segmentation based on deep learning.•Trained and validated in 90 km long railway and tested in three new scenarios with different characteristics.•Generalization to new railway environments and Lidar sensors.
Rail transport is a continuous process that must be coordinated at all levels of management and is determined by technological processes. From a technological point of view, it is important to ...correctly determine the practical throughput of the track section, also called the railway infrastructure capacity. This means how much train traffic can be used to load the track section so that it shows sufficient train traffic stability even in the event of operational irregularities. The article is focused on the method of increasing the capacity of the Drienovská Nová Ves - Kysak track section with using the application of the method of determining the practical throughput performance in the anticipated timetable. Detailed determination of the occupation times of the section in the current state and in the application of individual proposals to increase the capacity of the investigated railway line provide us with information on other possibilities of modernization of the railway infrastructure in Slovak Republic. The article describes and evaluates the advantages and disadvantages of individual proposals to increase capacity of the track section. As part of the future modernization of the railway infrastructure of this track section, it is necessary to implement these measures, as the track section under investigation is part of the AGTC and TEN-T international railway corridors. When designing new corridors, it is necessary to analyse and optimize the current railway network. The intention is not only to increase the quality of railway infrastructure, but also the quality of goods and passenger transport.
In Poland, due to the increase in investments made by railways in recent years, and thus the increase in the replacement value of transport infrastructure, the need for expenditure on infrastructure ...maintenance will increase in the next 30 years, or the development of the developed transport network will degrade. As part of the overall discipline of resource management, subdiscipline has emerged - infrastructure asset management. As part of the management of railway transport infrastructure, the demand for cheaper maintenance costs will grow. The cost reduction of infrastructure maintenance is possible through meticulous assessment of its condition, rational selection of locations and scope of repairs at the assumed risk level, as well as at the stage of preparation of new construction or modernization projects taking into account aspects of later maintenance. For some time, we have been observing the accumulation of knowledge (methods, programs, procedures) in the country and abroad enabling optimization of infrastructure condition assessment and programming of its maintenance. The implementation of these solutions may result in a more rational use of funds for infrastructure maintenance and not disturb its smooth functioning in operation. The article discusses aspects that should be considered in the design process of railway infrastructure. Particular attention was paid to the durability of steel components of the railway superstructure, maintenance costs as well as aspects related to the capacity of the track node. An example of dependence of selected values of radial arcs depending on their durability and maintenance costs was presented. It was proposed to change the track layout at the Warszawa Srodmiescie passenger stop planned for reconstruction. Calculations of kinematic parameters for various configurations of railway turnouts were performed. Also, calculations of the capacity for the existing track system solution as well as the proposed track system after reconstruction of the analysed Warszawa Srodmiescie railway station were also carried out.
The level of development of railway transport is one of the indicators of the economic development of the state. If the state regularly invests in large volumes in railway infrastructure, it creates ...conditions for the operation of quality passenger and freight rail transport. Analytical comparison of railway infrastructures is key to understanding the increasingly abysmal differences between the quality of railway infrastructure in the two countries. The comparison will be made mainly from the Network Statement of both countries.
•A generic solution approach applicable to discrete types of infrastructure assets.•Development of predictive models for efficient maintenance of railway switches.•Utilize data from an in-use ...business process from a real railway agency.•Explanation of the models’ performance by feature and instance level interpretation.
With growing service demands, rapid deterioration due to extensive usage, and limited maintenance due to budget cuts, the railway infrastructure is in a critical state and require continuous maintenance. The infrastructure managers have to come up with smart maintenance decisions in order to improve the assets’ condition, spend optimal cost and keep the network available. Currently, the infrastructure managers lack the tools and decision support models that could assist them in taking (un) planned maintenance decisions effectively and efficiently. Recently, many literature studies have proposed to employ the machine learning techniques to estimate the performance state of an asset, predict the maintenance need, possible failure modes, and such similar aspects in advance. Most of these studies have utilised additional data collection measures to record the assets’ behaviour. Though useful for experimentation, it is expensive and impractical to mount monitoring devices on multiple assets across the network. Therefore, the objective of this study is to develop predictive models that utilise existing data from a railway agency and yield interpretable results. We propose to leverage the tree-based classification techniques of machine learning in order to predict maintenance need, activity type and trigger’s status of railway switches. Using the data from an in-use business process, predictive models based on the decision tree, random forest, and gradient boosted trees are developed. Moreover, to facilitate in models interpretability, we provided a detail explanation of models’ predictions by features importance analysis and instance level details. Our solution approach of predictive models development and their results explanation have wider applicability and can be used for other asset types and different (maintenance) planning scenarios.
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