Sleeper end resistance of ballasted railway tracks

This paper describes model tests used to investigate how ballast shoulder width and height contribute to a railway sleeper’s resistance to lateral movement for a range of shoulder widths and heights. Deflection and resistance were measured and photographs taken during the tests.The photographs were analyzed using a digital image correlation technique to identify the zones of ballast surface disturbance, which demonstrated that a bulbed failure volume was mobilized at the ultimate limit state. An idealized three-dimensional failure mechanism is proposed, and resistances are calculated using the limit equilibrium approach. The calculation provides a reliable estimate of the measured resistance. The work identifies the optimum shoulder width and height. The calculations are extended to demonstrate that when a number of sleepers are moved simultaneously, the sleeper end resistance may be one-third less per sleeper than that indicated in tests on an isolated sleeper. Image analysis and limit equilibrium calculations show that this is caused by overlapping of mobilized failure volumes from adjacent sleepers

Impact of Sand Drifts on Jordanian Railway Infrastructures: Alternatives and Mitigation Measures

Railways play a critical role in connecting urban and rural regions, thereby promoting the economic sectors of a country. Nevertheless, railway tracks may suffer from several infrastructural problems and deficiencies including sand drifts, particularly in arid and semi-arid regions. This research aims to provide an analytical review of sand-laden drifts and winds, and the measures that can alleviate their impacts on the Aqaba railway tracks, Jordan. It also studies the influence of phosphate deposition as a result of trucks’ passage on the railway tracks. General and practical recommendations from a socio-geographical context are also highlighted in view of proposing tactical solutions and identifying prospects for upcoming research to advance the technical and economical efficiency of the Jordanian railway network. Keywords: Sand drifts, wind, railway network, railway infrastructures, mitigation measures. DOI: 10.7176/CER/14-5-01 Publication date:August 31st 202

Numerical models of railway tracks for obtaining frequency response Comparison with analytical results and experimental measurements

Many authors have focused their research on the vibrations caused by railway traffic, and have developed diverse models of railway tracks: from half-track analytical models up to complex numerical models. This paper presents numerical models, built using FEM software, for different types of railway tracks. These models describe in detail the superstructure vibratory response induced by vertical forces acting on the top of the rail head, and include aspects not reflected in the analytical models. The numerical results are compared with previously presented analytical ones, as well as with experimental measurements

Dynamic response of railway tracks in tunnel

International audiencePeriodically supported beams subjected to a moving load are often used for modelling the railway dynamics and analytical solutions have been developed for such modelling [3, 4]. More complex models can be constructed by including supports with damping or non-linear stiffness elements. This study deals with the dynamical modelling of non-ballasted railways, especially railways in tunnels. The model is developed as a dynamical system of multi-degree of freedom. Under the periodic assumption on the reaction force of the supports, the equation of motion for a periodically supported beam subjected to a moving load has been written. Then the Fourier transform has been used to solve this equation in case of damped supports. Analytical solutions have been established for the motion of the wheel and rail and also for the reaction force of the supports. The analytical solutions have been compared with in situ experimental measurements. The comparison shows that the theoretical results agree well with the measured results if damped supports are included in the model

Rock falls impacting railway tracks. Detection analysis through an artificial intelligence camera prototype

During the last few years, several approaches have been proposed to improve early warning systems for managing geological risk due to landslides, where important infrastructures (such as railways, highways, pipelines, and aqueducts) are exposed elements. In this regard, an Artificial intelligence Camera Prototype (AiCP) for real-time monitoring has been integrated in a multisensor monitoring system devoted to rock fall detection. An abandoned limestone quarry was chosen at Acuto (central Italy) as test-site for verifying the reliability of the integratedmonitoring system. A portion of jointed rockmass, with dimensions suitable for optical monitoring, was instrumented by extensometers. One meter of railway track was used as a target for fallen blocks and a weather station was installed nearby. Main goals of the test were (i) evaluating the reliability of the AiCP and (ii) detecting rock blocks that reach the railway track by the AiCP. At this aim, several experiments were carried out by throwing rock blocks over the railway track. During these experiments, the AiCP detected the blocks and automatically transmitted an alarm signal

Toilets and Trains

<div align=justify>Indian Railways (IR) is a large transport organization running 8700 trains, reaching 7000 stations and handling about 1.6 crore passengers per day. IR runs several long distant trains, some of which involve journeys upto three nights. The number of non suburban passengers traveling on IR is about 0.6 crore per day. There are three sources of fecal matter generation in IR (i) Toilets in trains, (ii) Railway stations; and (iii) Use of railway tracks for open defecation. The existing toilet system in the coaches discharges excreta directly to the ground and the railway tracks. The consequences include unacceptable hygienic conditions, particularly in the railway stations, and damage to rails. IR is making efforts to introduce environment friendly toilet discharge system, for which three options are being considered; modular, vacuum and chemical. Toilets at stations are a part of amenities being provided, linked to the category of the station. There is an attempt to modernize toilets at important stations. A related socio economic problem is that of people residing near the railway stations, without access to toilet facilities, using tracks for open defecation. The issue of dealing with fecal matter should be viewed in the larger context of waste management. With effective waste management, fecal matter can be recycled and used as liquid fertilizers and quality organic manures. This paper attempts to understand the issues related to fecal matter management on the IR, and provide a framework for solutions.</div>

Thermal and mechanical behavior of railway tracks

Mestrado de dupla diplomação com a UTFPR - Universidade Tecnológica Federal do ParanáRailways are infrastructures subject to open weather conditions and also to temperature changes during the day and over the season. Due to this change, internal stresses may appear, whether tensile or compressive depending on the stress-free temperature and the current measure. High compressive stress may lead the track to buckle, meanwhile tensile stress can cause brittle failure. Given the importance of the temperature on railways, many models have been developed to correlate weather conditions and rail temperatures, in order to avoid the occurrence of mechanical instabilities which cause major problems in the operation of railroads. The present work validates one model developed by CNU university by comparing it with nite element solutions and also with experimental data of a rail track in the city of Mirandela-Portugal. A python package was developed to solve the model and is available to download. The model shows a good correlation between measured and simulated rail temperatures. In addition, by utilizing weather information of other locations in Portugal, the maximum expected rail temperatures were determined. Furthermore, mechanical analyses were made to analyze the critical temperature to reach the buckling mode of instability without the e ect of rolling loads and also the important parameters that a ect this phenomenon. The simulations show that the quality of the ballast and the initial miss-alignment of the track are the most important. Keywords:Caminhos de ferro s~ao estruturas expostas a uma grande variedade de condi c~oes clim aticas e, concretamente a varia c~oes de temperatura durante o dia e ao longo das esta c~oes durante o ano. Devido a estas varia c~oes tens~oes internas ocorrem, podendo ser esfor cos de compress~ao ou tra c~ao, dependendo da temperatura neutral do per l. A ocorr^encia de tens~oes de compress~ao elevadas pode causar encurvadura da via, enquanto que os esfor cos de tra c~ao podem ocasionar a fratura fr agil. Devido a import^ancia das temperaturas nas vias f erreas, muitos modelos t^em sido desenvolvidos para correlacionar condi c~oes clim aticas com a temperatura da via tendo em vista o seu uso como ferramenta de preven c~ao de acidentes na opera c~ao. O presente trabalho utiliza um destes modelos, desenvolvido pela universidade CNU e valida-o utilizando solu c~oes com o m etodo dos elementos nitos e, tamb em, com dados experimentais de uma via f errea localizada na cidade de Mirandela-Portugal. Foi ainda desenvolvido um software utilizando a linguagem Python para facilitar a solu c~ao do modelo, estando ainda dispon vel para download. O modelo demonstrou boa correla c~ao entre as temperaturas simuladas e medidas. Al em disso, utilizando informa c~oes meteorol ogicas de outras localidades em Portugal, as temperaturas m aximas esperada das vias foram determinadas. Posteriormente, an alises mec^anicas de encurvadura foram realizadas para determinar em quais temperaturas uma via ferra pode sofrer encurvadura e, tamb em, quais par^ametros que in uenciam este fen^omeno. As simula c~oes mostram que a qualidade do balastro e as imperfei c~oes iniciais da via s~ao os mais importantes

The Material and Immaterial Urban Remains of a Railway Heritage – the case of Araraquara/SP (Brazil)

The Araraquara Railway Station was built in 1885 as a symbol of prosperity. With the passing time it turned to be something indifferent to the city population, being deactivated in 2015. The railway remains are the result of many spatial and cultural changes; they can be discussed as a material or an immaterial heritage, which reinforces the importance of the railway history. This infrastructure is a part of Araraquara history, its remains should be appreciated, reintegrated and reused as the core to save a memory disregarded over the years.Centro Interdisciplinar de História, Culturas e Sociedades - CIDEHUS - UID/HIS/00057/2013 (POCI-01-0145-FEDER-007702