scholarly journals Investigation of the reinforcement and stabilisation effect of geogrid layers under railway ballast

2011 ◽  
Vol 19 (3) ◽  
pp. 22-30 ◽  
Author(s):  
Sz. Fischer ◽  
F. Horvát
Keyword(s):  
Research Team ◽  
Research Topic ◽  
Transport Infrastructure ◽  
Railway Track ◽  
Railway Ballast ◽  
Track Geometry ◽  
Municipal Engineering ◽  
New Research

Investigation of the reinforcement and stabilisation effect of geogrid layers under railway ballastThis paper deals with the issue of the stabilization of railway track geometry. It details the published results in numerous international journals. Having analysed the cited publications the paper deals with a new research topic related to geogrid-reinforced railway ballast. A research team of the Department of Transport Infrastructure and Municipal Engineering at the Szechenyi Istvan University would like to continue working on this research topic.

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 Development of fragility curves for railway ballast and embankment scour due to overtopping flood flow

2016 ◽  
Author(s):  
Ryota Tsubaki ◽  
Koji Ichii ◽  
Jeremy D. Bricker ◽  
Yoshihisa Kawahara
Keyword(s):  
Spatial Distribution ◽  
Failure Probability ◽  
Fragility Curves ◽  
Railway Track ◽  
Single Track ◽  
Hydraulic Analysis ◽  
Railway Ballast ◽  
Log Normal ◽  
Flood Flow

Abstract. Fragility curves evaluating risk of railway track ballast and embankment fill scour were developed. To develop fragility curves, two well-documented single-track railway washouts during two recent floods in Japan were investigated. Type of damage to the railway was categorized into no damage, ballast scour, and embankment scour, in order of damage severity. Railway overtopping surcharge for each event was estimated via hydrologic and hydraulic analysis. Normal and log-normal fragility curves were developed based on failure probability derived from field records. A combined ballast and embankment scour model was validated by comparing the spatial distribution of railway scour with the field damage record.

scholarly journals Micro-mechanical investigation of railway ballast behavior under cyclic loading in a box test using DEM: effects of elastic layers and ballast types

2019 ◽  
Vol 21 (4) ◽  
Author(s):  
Nishant Kumar ◽  
Bettina Suhr ◽  
Stefan Marschnig ◽  
Peter Dietmaier ◽  
Christof Marte ◽  
...  
Keyword(s):  
Cyclic Loading ◽  
Early Stage ◽  
Damage Model ◽  
Simulation Models ◽  
Railway Track ◽  
Maintenance Cost ◽  
Particle Movement ◽  
Railway Ballast ◽  
Elastic Layers ◽  
The Impact

Abstract Ballasted tracks are the commonly used railway track systems with constant demands for reducing maintenance cost and improved performance. Elastic layers are increasingly used for improving ballasted tracks. In order to better understand the effects of elastic layers, physical understanding at the ballast particle level is crucial. Here, discrete element method (DEM) is used to investigate the effects of elastic layers – under sleeper pad ($$\text {USP}$$USP) at the sleeper/ballast interface and under ballast mat ($$\text {UBM}$$UBM) at the ballast/bottom interface – on micro-mechanical behavior of railway ballast. In the DEM model, the Conical Damage Model (CDM) is used for contact modelling. This model was calibrated in Suhr et al. (Granul Matter 20(4):70, 2018) for the simulation of two different types of ballast. The CDM model accounts for particle edge breakage, which is an important phenomenon especially at the early stage of a tamping cycle, and thus essential, when investigating the impact of elastic layers in the ballast bed. DEM results confirm that during cyclic loading, $$\text {USP}$$USP reduces the edge breakage at the sleeper/ballast interface. On the other hand, $$\text {UBM}$$UBM shows higher particle movement throughout the ballast bed. Both the edge breakage and particle movement in the ballast bed are found to influence the sleeper settlement. Micro-mechanical investigations show that the force chain in deeper regions of the ballast bed is less affected by $$\text {USP}$$USP for the two types of ballast. Conversely, dense lateral forces near to the box bottom were seen with $$\text {UBM}$$UBM. The findings are in good (qualitative) agreement with the experimental observations. Thus, DEM simulations can aid to better understand the micro-macro phenomena for railway ballast. This can help to improve the track components and track design based on simulation models taking into account the physical behavior of ballast. Graphical Abstract

scholarly journals The Design and Implementation of an Inertial GNSS Odometer Integrated Navigation System Based on a Federated Kalman Filter for High-Speed Railway Track Inspection

2021 ◽  
Vol 11 (11) ◽  
pp. 5244
Author(s):  
Xinchun Zhang ◽  
Ximin Cui ◽  
Bo Huang
Keyword(s):  
Kalman Filter ◽  
Navigation System ◽  
High Speed ◽  
Measurement Accuracy ◽  
Railway Track ◽  
Filter Method ◽  
Integrated Navigation ◽  
High Speed Railway ◽  
Track Geometry ◽  
Integrated Navigation System

The detection of track geometry parameters is essential for the safety of high-speed railway operation. To improve the accuracy and efficiency of the state detector of track geometry parameters, in this study we propose an inertial GNSS odometer integrated navigation system based on the federated Kalman, and a corresponding inertial track measurement system was also developed. This paper systematically introduces the construction process for the Kalman filter and data smoothing algorithm based on forward filtering and reverse smoothing. The engineering results show that the measurement accuracy of the track geometry parameters was better than 0.2 mm, and the detection speed was about 3 km/h. Thus, compared with the traditional Kalman filter method, the proposed design improved the measurement accuracy and met the requirements for the detection of geometric parameters of high-speed railway tracks.

Railway track irregularity and curvature estimation using doppler LIDAR fiber optics

2016 ◽  
Vol 232 (1) ◽  
pp. 63-72 ◽  
Author(s):  
Masood Taheri Andani ◽  
Andrew Peterson ◽  
Josh Munoz ◽  
Mehdi Ahmadian
Keyword(s):  
Fiber Optics ◽  
Field Testing ◽  
Railway Track ◽  
Vehicle Speed ◽  
Doppler Lidar ◽  
Close Match ◽  
Track Geometry ◽  
Lidar Measurements ◽  
Curvature Estimation ◽  
Geometry Measurement

The application of Doppler-based LIght Detection and Ranging (LIDAR) technology for determining track curvature and lateral irregularities, including alignment and gage variation, are investigated. The proposed method uses track measurements by two low-elevation, slightly tilted LIDAR sensors nominally pointed at the rail gage face on each track. The Doppler LIDAR lenses are installed with a slight forward angle to measure track speed in both longitudinal and lateral directions. The lateral speed measurements are processed for assessing the track gage and alignment variations, using a method that is based on the frequency bandwidth dissimilarities between the vehicle speed and track geometry irregularity. Using the results from an extensive series of tests with a body-mounted Doppler LIDAR system on-board a track geometry measurement railcar, the study indicates a close match between the LIDAR measurements and those made with existing sensors on-board the railcar. The field testing conducted during this study indicates that LIDAR sensors could provide a reliable, non-contact track monitoring instrument for field use in various weather and track conditions, potentially in a semi-autonomous or autonomous manner.

The creation of new research system for the investigation of surface quality by stones

2013 ◽  
Vol 4 (1) ◽  
pp. 43-48
Author(s):  
I. G. Gyurika ◽  
M. Gálos
Keyword(s):  
Research Team ◽  
Face Milling ◽  
Average Surface Roughness ◽  
Research System ◽  
Machining Processes ◽  
Average Surface ◽  
Milling Operations ◽  
University Of Technology ◽  
New Research ◽  
Cutting Speeds

Abstract The research on automated stone machining processes was very significant in the last two decades. Sawing, cutting and grinding of different stones like granite, marble, limestone became cheaper and more productive because of the results of researches. When searching through international specialised literature in the topic of stone machining with machine centres, theoretical summaries or researches can hardly be found. The aim of the researchers writing this article is — as a pioneer in Hungary, but also among the first internationally — to examine the optimization and technological problems in the area of stone milling processes. The researchers have developed a complex research system with the collaboration of two departments of University of Technology and Economics and an industrial stone machining firm, Woldem Ltd. to solve the problems. This paper summarizes the parts of this system. General steps and results of research processes are demonstrated by reference experiments. Face milling operations were made on a granite block with five different cutting speeds and then the researchers measured slip safety and average surface roughness values in case of different samples. Finally, upcoming tasks of the research team are summarized.

scholarly journals A knowledge-based prognostics framework for railway track geometry degradation

2019 ◽  
Vol 181 ◽  
pp. 127-141 ◽  
Author(s):  
Juan Chiachío ◽  
Manuel Chiachío ◽  
Darren Prescott ◽  
John Andrews
Keyword(s):  
Railway Track ◽  
Track Geometry ◽  
Knowledge Based

Conclusion

2016 ◽  
pp. 345-351 ◽  
Author(s):  
Lorraine Ling ◽  
Peter Ling
Keyword(s):  
Education Research ◽  
Research Topic ◽  
Research Paradigm ◽  
Research Paradigms ◽  
The World ◽  
New Research

Authors of the chapters of this book have reflected on education research undertakings and research paradigms applicable to their work. Their writing is revisited here as it links education research in practice to underpinning understandings of the nature of the aspect of the world investigated, the drivers of the research and the contributions to knowledge that emerge. Instances that fit within or move between established research paradigms are addressed first. The case for a new research paradigm—the supercomplexity paradigm—is then rehearsed and contributions of chapter authors to that concept and its application summarized. While research reviewed in the chapters covers the full array of paradigms, the endeavors portrayed are linked by the act of research itself. In this endeavor, whatever the education research topic, approach and methods employed, being clear about the research paradigm that applies helps in ensuring the research exercise is coherent and the outcomes appropriate and defensible.

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