scholarly journals The impact of summer heatwaves on railway track geometry maintenance

2021 ◽  
pp. 095440972098429
Author(s):  
Ben Davies ◽  
John Andrews
Keyword(s):  
Asset Management ◽  
Response Times ◽  
Railway Track ◽  
Management Support ◽  
Maintenance Policy ◽  
Management Tools ◽  
Support Tool ◽  
Track Geometry ◽  
Maintenance Activities ◽  
The Impact

Elevated summer temperatures are a disrupting factor on the rail network. Due to the risk of a track buckling under thermal expansion forces, geometry maintenance must be delayed during heatwaves, leading to an overall decreased network availability and reliability. Track asset management support tools are used to plan and schedule a variety of maintenance activities, with tamping and stoneblowing being the primary activities for geometry maintenance. No management tools seen in the literature consider the influences of weather on the scheduling and delivery of maintenance. This paper describes a Petri net modelling approach to railway track asset management. This is demonstrated to be a highly flexible method able to capture the complexities of degradation, inspection, and maintenance, and predict the evolution of track geometry quality over time. Different maintenance strategies are tested, varying the degradation thresholds, inspection intervals, policy decisions, and maintenance response times. Excessively hot weather is introduced as an inhibiting factor for all maintenance activities, resulting in extended periods where interventions are delayed. Simulation results show that frequent inspection and timely maintenance scheduling strategies could be followed to attain a highly performing and resilient track system. This asset management support tool could be added to the suite used by the rail industry, providing guidance on maintenance policy through a summer season where heatwave disruptions are expected.

Monte Carlo simulation of railway track geometry deterioration and restoration

2011 ◽  
Vol 226 (3) ◽  
pp. 274-282 ◽  
Author(s):  
L M Quiroga ◽  
E Schnieder
Keyword(s):  
High Speed ◽  
Railway Track ◽  
Ageing Process ◽  
Previous Knowledge ◽  
Planning And Scheduling ◽  
Track Geometry ◽  
Marquardt Algorithm ◽  
Non Linear ◽  
Maintenance Activities ◽  
Parameter Values

Travelling safely and comfortably on high-speed railway lines requires excellent conditions of the whole railway infrastructure in general and of the railway track geometry in particular. The maintenance process required to achieve such excellent conditions is complex and expensive, demanding a large amount of both human and technical resources. In this framework, choosing the right maintenance strategy becomes a critical issue. A reliable simulation of the railway geometry ageing process would offer a great advantage for the optimization of planning and scheduling of maintenance activities. A fundamental requirement for such simulation is a statistical model describing the behaviour of the railway track geometry deterioration as well as the effects of maintenance activities. The French railway operator SNCF has been periodically measuring the geometrical characteristics of its high-speed network since its commissioning (i.e. for more than 20 years now). These records are an excellent data source to achieve a sound statistical description of the process. In this paper a new system identification method to obtain such simulations is presented. The proposed method uses a grey-box model: a model structure and its constraints are specified basing on previous knowledge of the process to be identified, and then the set of parameter values which best fits the signal measurements is searched. As previous knowledge indicates that the process is non-linear, parameter values are searched by means of the Levenberg–Marquardt algorithm, an iterative technique that finds a local minimum of a function that is expressed as the sum of squares of non-linear functions. Furthermore, the presented model is extended in order to analyse the effect of the variation of factors influencing the ageing process (e.g. operational speed). Finally, the method is applied and validated with real data of a French high-speed TGV line.

scholarly journals Preliminary study of shaping the railway track geometry in terms of their maintenance costs and capacity

2020 ◽  
Vol 53 (1) ◽  
pp. 115-128 ◽  
Author(s):  
Piotr Gołębiowski ◽  
Jacek Kukulski
Keyword(s):  
Asset Management ◽  
Transport Infrastructure ◽  
Railway Track ◽  
Risk Level ◽  
Maintenance Costs ◽  
Track Geometry ◽  
Track System ◽  
System Solution ◽  
New Construction ◽  
Infrastructure Maintenance

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.

scholarly journals Effective time interval for railway track geometry inspection

2020 ◽  
Vol 53 (1) ◽  
pp. 53-65 ◽  
Author(s):  
Ahmad Kasraei ◽  
Jabbar Ali Zakeri
Keyword(s):  
Decision Making ◽  
Railway Track ◽  
Sensitivity Analyses ◽  
Maintenance Cost ◽  
Time Interval ◽  
Maintenance Policy ◽  
Corrective Maintenance ◽  
Track Geometry ◽  
Inspection Interval ◽  
Geometry Inspection

A proper decision-making scheme for track geometry maintenance requires a knowledge of the real condition of track geometry. Therefore, the track must be inspected by measurement cars at different time intervals. The frequency of track geometry inspection plays a crucial role in decision-making and has always been a big concern for infrastructure managers. The inspection interval should be chosen properly, it means that the small period can decrease the capacity of line and affect the operation of network and the big period can result in low quality of track and in some cases derailments and possible loss of human lives. The aim of this paper is to determine the effective inspection interval such that the total maintenance cost is minimized. In the proposed cost model, the costs of inspection, preventive maintenance, corrective maintenance and the penalty for exceeding the corrective maintenance level are considered. A case study is performed on a real dataset collected from a railway line in Iran. The standard deviation of longitudinal level is considered to measure track geometry degradation. A widely applied linear model is used to model track geometry degradation over time. Monte Carlo technique is used to simulate the track geometry behavior under various track geometry inspection intervals. In addition, a set of sensitivity analyses are carried out to assess the effect of various inspection intervals on different terms of maintenance cost. The results indicate that not only can substantial costs be saved by setting effective inspection intervals, but also the time during which the track suffers from bad conditions is dramatically reduced. The result of this study has shown the appropriate inspection interval for the studied case can result in 13.6 percent decrease in maintenance cost in comparison with the current maintenance policy. Besides, it would lead to more reliable railway track by preventing the system exceed the corrective threshold.

scholarly journals The impact of organizational support on project efficiency: evidence from Kazakhstan

2020 ◽  
Vol 18 (4) ◽  
pp. 203-212
Author(s):  
Orazaly Sabden ◽  
Assel Kozhakhmetova ◽  
Aknur Zhidebekkyzy ◽  
Sharbanu Turdalina
Keyword(s):  
Organizational Support ◽  
Quantitative Research ◽  
Service Industry ◽  
Project Managers ◽  
Management Support ◽  
Cost Overrun ◽  
Management Tools ◽  
The Republic ◽  
Using Data ◽  
The Impact

Project managers from different areas struggle to find universal set of factors to achieve high project efficiency. However, the project efficiency assessment varies across industries, making it difficult to apply general concepts and guidelines in the specific project environment. The study’s main purpose is to assess the impact of organizational support on project efficiency in different areas and identify critical processes that increase it. The paper presents quantitative research results by using data from 261 project managers in the Republic of Kazakhstan during 2018–2019. The research sample consists of commercialization projects, scientific projects, social projects, and projects from the service industry. The research findings show the different quality levels of top management support and its high correlation with project efficiency. Furthermore, the study reveals the specific processes for each investigated type of project that highly correlate with project efficiency dimensions. Commercialization projects that intensively use the organizational support processes were the most efficient projects by showing the best result in cost overrun (15%) and the second resulted in schedule overrun (17%). These findings have theoretical and practical implications, supporting project managers in increasing their project efficiency by choosing the critical, proper project management tools and techniques.

scholarly journals Railway track availability modelling with opportunistic maintenance practice

2021 ◽  
pp. 095440972110476
Author(s):  
Ben Davies ◽  
John Andrews
Keyword(s):  
Asset Management ◽  
Ride Comfort ◽  
Management Strategies ◽  
Railway Track ◽  
Management Tool ◽  
Maintenance Strategy ◽  
Combined System ◽  
Opportunistic Maintenance ◽  
Track Geometry ◽  
Maintenance Practice

The geometry of railway track must be maintained within certain standards in order to provide a highly available network, as well as good ride comfort and safety for all rail users. Modelling is well utilised as part of asset management tools in exploring the effectiveness of different rail geometry maintenance strategies. By considering the rail route as an entire system – in contrast to a track section in isolation – a more effective maintenance strategy can be developed, including the deployment of opportunistic maintenance practice. This study presents a Coloured Petri Net model of railway track degradation, inspection, and maintenance planning and delivery, for an entire route of track sections. Opportunistic maintenance is introduced through a novel search transition function, which groups interventions based on local adjacency. Testing explores the availability and maintenance demands expected when following a series of different management strategies. This is extended to testing under heatwave conditions, a known disrupter to track geometry maintenance delivery. Simulation results show that in following an opportunistic strategy, greater availability can be achieved on the modelled rail line. Further, resilience to the heatwave disruptions can be achieved by selecting the correct maintenance strategy parameters. This asset management tool can provide guidance on management strategies for a full route of track sections as a combined system.

scholarly journals Delayed maintenance modelling considering speed restriction for a railway section

2017 ◽  
Vol 231 (4) ◽  
pp. 411-428
Author(s):  
Hui Shang ◽  
Christophe Bérenguer ◽  
John Andrews
Keyword(s):  
Survival Time ◽  
Preventive Maintenance ◽  
Railway Track ◽  
System Throughput ◽  
Maintenance Cost ◽  
Decision Variable ◽  
Track Geometry ◽  
Coloured Petri Net ◽  
Maintenance Activities ◽  
System Benefit

The deterioration of track geometry depends on several factors of which the speed of the train is one. Imposing a speed restriction can slow down the track deterioration and allows a longer survival time before a serious condition is achieved. Preventive maintenance delays can be authorized during the survival time. However, speed restrictions also reduce the system throughput. On the other hand, a longer interval between preventive maintenance activities has a lower maintenance action cost and it also enables grouping the maintenance activities to save set-up costs as well as system downtime. If the repair delay is too long, it may cause unacceptable conditions on the track and lead to higher maintenance costs and accidents. Therefore, it is interesting to assess the effect of a speed restriction on the delayed maintenance strategies for a railway track section. We want to solve a maintenance optimization problem to find the optimal tuning of the maintenance delay time and imposition of a speed restriction. To this aim, a delayed maintenance model is developed, in which track deterioration depends on the train speed and the number of passing trains. The model is used to determine an optimal speed restriction strategy and a preventive repair delay for the optimization of the system benefit and unavailability. Coloured Petri Nets are adopted to model the maintenance and operation of the railway track section. The Coloured Petri Net model describes the gradual track deterioration as a stochastic process. Different speed restriction policies and maintenance delay strategies are modelled and activated by the observed component states. Monte Carlo simulations are carried out to estimate the maintenance cost, the system benefit and the system downtime under different policies. Numerical results show the maintenance decision variable trade-off.

scholarly journals GEOPROCESSAMENTO APLICADO AO ESTUDO DE VULNERABILIDADE DO SOLO DA BACIA HIDROGRÁFICA DO CÓRREGO GUARIBAS EM UBERLÂNDIA-MG

2017 ◽  
Vol 13 (2) ◽  
Author(s):  
Erich Vectore Pavanin ◽  
Maria Lígia Chuerubim ◽  
Bruno De Oliveira Lázaro
Keyword(s):  
Urban Planning ◽  
Stream Water ◽  
Multicriteria Analysis ◽  
Ground Level ◽  
Digital Processing ◽  
Management Tools ◽  
Support Tool ◽  
Unconsolidated Material ◽  
The Impact ◽  
Hierarchy Process

RESUMO: Este trabalho apresenta um estudo acerca da aplicação de técnicas de geoprocessamento na definição e caracterização dos graus de vulnerabilidade geotécnica do solo na Bacia Hidrográfica do Córrego Guariba em Uberlândia – MG. Observou-se, na área de estudo, ser necessário o estabelecimento de ferramentas de planejamento e gestão territorial que possibilitassem analisar e verificar o impacto da ocupação antrópica nas margens de córregos urbanos frente à ocorrência de processos erosivos. Desta maneira, o uso de geotecnologias, como o Sensoriamento Remoto, inseriu-se neste tipo de trabalho como sendo um mecanismo indispensável ao planejamento urbano, dado possibilitar, mediante a utilização de imagens de satélite e ferramentas de processamento digital, o mapeamento e caracterização geotécnica das bacias hidrográficas localizadas no Brasil. Nesta perspectiva, foram utilizadas neste trabalho imagens de softwares livres do ano de 2013, bem como as ferramentas de processamento digital de imagens SPRINGS e AUTOCAD, com o intuito de identificar as classes de uso e ocupação do solo da área de estudo, a declividade da região, os tipos de materiais inconsolidados (solo) e a profundidade do nível d’água local. A partir do estabelecimento destes quatro planos de informação, utilizou-se o método de Análise de Multicritérios, denominado também AHP (Analystic Hierarchy Process), para correlacionar os dados obtidos e elaborar o mapa de vulnerabilidade do solo. Assim, este trabalho contribui para promover o diagnóstico da vulnerabilidade do solo à erosão na Bacia Hidrográfica do Córrego Guaribas em Uberlândia-MG e para a utilização deste dado como ferramenta de suporte no planejamento urbano sustentável.
 
 ABSTRACT: This paper presents a study on the application of GIS techniques to define and characterize the degree of geotechnical soil vulnerability in Guaribas Stream Water Basin in Uberlândia - MG. It was observed in the study area, be necessary to establish planning and land use management tools that make possible to analyze and verify the impact of human occupation on the banks of urban streams across the occurrence of erosion. Thus, the use of geo-technologies, such as remote sensing, inserted in this type of work as an indispensable mechanism to urban planning, as possible, through the use of satellite images and digital processing tools, mapping and geotechnical characterization river basins located in Brazil. In this perspective, we were used in this study of 2013 years of free software images, as well as the digital processing tools SPRINGS and AUTOCAD images, in order to identify the classes of use and land cover in the study area, the slope of the region, the types of unconsolidated material (ground) level and the depth d local water. From the establishment of these four planes of information, we used the Multicriteria Analysis method, also called AHP (Analystic Hierarchy Process) to correlate the data and prepare the vulnerability map of erosion in the catchment area of Guaribas Stream. In that way, this work helps to promote the diagnosis of soil vulnerability to erosion in the Basin Guaribas stream in Uberlândia-MG and to use this data as a support tool for sustainable urban planning.

scholarly journals An efficient physical-based method for predicting the long-term evolution of vertical railway track geometries

2021 ◽  
pp. 095440972110248
Author(s):  
Nishant Kumar ◽  
Claudia Kossmann ◽  
Stephan Scheriau ◽  
Klaus Six
Keyword(s):  
Long Term Evolution ◽  
Contact Forces ◽  
Railway Track ◽  
Model Parameters ◽  
Relative Height ◽  
Vehicle Model ◽  
Track Geometry ◽  
Term Evolution ◽  
Maintenance Activities

The dynamic wheel-rail contact forces resulting from the interaction between vehicle and track are responsible for the local track settlement. If these local settlements vary along the track, geometric irregularities develop further amplifying the dynamic loading of the track caused by the interaction between the vehicle and track. In this work, an efficient vehicle-track interaction (VTI) model is presented for predicting the long-term evolution of vertical track settlement during operation. The VTI model has two interacting components – vehicle and track. The vehicle model describes the vertical dynamics of an 8th of a car. The track model considers an elastic rail on discrete (sleeper) supports. Each sleeper location can have its own stiffness, relative height and settlement characteristics. Dependent on the distribution of stiffness and settlement behaviour along the track together with the initial track geometry, each sleeper settles dependent on the number of load cycles (vehicle passes). The track model is initialized with measured vertical track geometry data and static track deflection data at the beginning (day 0) for two types of track sections in the field, a track section where concrete sleepers with Under Sleeper Pads (USP) are used and a track section where only concrete sleepers are used. Using the same settlement model parameters (constant along the track) for the two tracks, the physical-based VTI model can predict the different track geometry quality evolution for both tracks over 350 days. Finally, the VTI model is used to assess the track geometry deterioration when the track/vehicle properties are changed. The prediction strength of the fast VTI model based on the physical understanding can assist in designing and optimizing tracks and in supporting of maintenance activities.

scholarly journals The role of track stiffness and its spatial variability on long-term track quality deterioration

2018 ◽  
Vol 233 (1) ◽  
pp. 16-32 ◽  
Author(s):  
I Grossoni ◽  
AR Andrade ◽  
Y Bezin ◽  
S Neves
Keyword(s):  
Spatial Variability ◽  
Computational Experiments ◽  
Railway Track ◽  
Track Geometry ◽  
Track Stiffness ◽  
Physical Variables ◽  
The Impact ◽  
Track Quality

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.

scholarly journals A risk-informed decision support tool for the strategic asset management of railway track infrastructure

2021 ◽  
pp. 095440972110383
Author(s):  
Manu Sasidharan ◽  
Michael Peter Nicholas Burrow ◽  
Gurmel Singh Ghataora ◽  
Rishi Marathu
Keyword(s):  
Asset Management ◽  
Safety Data ◽  
Decision Support Tool ◽  
Railway Track ◽  
Railway Network ◽  
Support Tool ◽  
Monte Carlo Simulation Technique ◽  
Track Maintenance ◽  
Cycle Basis ◽  
The Uk

The provision of safe, efficient, reliable and affordable railway transport requires the railway track infrastructure to be maintained to an appropriate condition. Given the constrained budgets under which the infrastructure is managed, maintenance needs to be predicted in advance of track failure, prioritized and identified risks and uncertainties need to be considered within the decision-making process. This paper describes a risk-informed approach that can be used to economically justify railway track infrastructure conditions by comparing on a life-cycle basis infrastructure maintenance costs, train operating costs, travel time costs, safety, social and environmental impacts. The approach represents a step-change for the railway industry as it will enable economic maintenance standards to be derived which considers the needs of the infrastructure operator, but also those of users, train operating companies and the environment. Further, the risk-informed capability of the tool enables asset managers to deal with uncertainties associated with forecasting costs and the effects of track maintenance, and unavailability of data. The Monte Carlo simulation technique and a Fuzzy reasoning approach are used to address safety data uncertainties through probabilistic risk assessment allied to expert opinion. The approach is illustrated using data from three routes on the UK mainline railway network. The results demonstrate that the approach can be used to support strategic and tactical levels of railway asset management to inform plausible design and maintenance strategies that realise the maximum benefit for the available budget.

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