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electromagnetic properties railway ballast research

Electromagnetic properties of railway ballast ScienceDirect

Jul 01, 2001· To investigate whether the condition of the railway ballast can be classified by the dielectric constant, ε r, — or the velocity of propagation of electromagnetic waves. 2. The suitability of the 500 or the 900 MHz GPR antennas in providing adequate penetration and of producing clear images of acceptable resolution. 3.

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Electromagnetic properties of railway ballast ScienceDirect

Laboratory experiments were undertaken to identify and characterise the dielectric properties of railway track ballast using Ground Penetrating Radar (GPR). Better results were obtained with lower frequency antennas. Clear distinctions were obtained between wet and dry and clean and spent ballast.

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Benchmarking large scale GPR experiments on railway ballast

Sep 01, 2015· The overall aim of this project was to relate ground penetrating radar (GPR) to a ballast fouling index (FI). Laboratory research aimed at characterising the electromagnetic properties has enabled researchers worldwide to determine ballast thickness using impulse ground penetrating radar (GPR) based upon derived values of the relative electrical permittivity or dielectric constant.

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(PDF) Railway Ballast Monitoring by GPR: A Test Site

These were towed along the rail sections by means of a dedicated railway cart. Main electromagnetic parameters of railway ballast were estimated for each scenario using time- and frequency-domain

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(PDF) Ballast fouling evaluation with ground penetrating radar

Particularly in the field of railway research, ballast is the key element, and its fouling leads to track deterioration. 3.1 Electromagnetic properties of mater The physical condition of

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Research on Railroad Ballast Specification and Evaluation

Research on Railroad Ballast Specification and Evaluation GERALD P. RAYMOND rock, slag, and gravel railway ballast sources are summarized in this paper. Comments are included about the new Canadian Pacific Rail ballast specif i­ These two properties, texture and composition, are

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[PDF] ASSESSMENT OF RAILWAY TRACK SUBSTRUCTURE

Ground penetrating radar (GPR) has been employed to assess railway track substructure (ballast, subballast, and subgrade) conditions. GPR involves transmitting radar pulses into the substructure and measuring return signals that have reflected off boundaries between substructure layers with different electromagnetic properties. The principle electromagnetic property of the layers is the

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Geotechnical properties of ballast and Research Online

ballast deformation and degradation under different con-ditions. A flowchart of the experimental programme, conducted by the authors on railway ballast based on large-scale triaxial testing, is shown in Fig. 1. Ballast behaviour. Ballast is a free-draining granular material used as a load-bearing material in railway tracks. It is composed of

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(PDF) Model Track Studies by Ground Penetrating Radar (GPR

Laboratory experiments were undertaken to identify and characterise the dielectric properties of railway track ballast using Ground Penetrating Radar (GPR). Better results were obtained with lower

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Understanding the capabilities of GPR for the measurement

The method is attractive, due Find, read and cite all the research you need on ResearchGate. Article. Understanding the capabilities of GPR for the measurement of Ballast fouling conditions.

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A Review of Methods for Estimating Ballast Degradation

Significant research has been conducted over the last two decades applying nondestructive ground-penetrating radar (GPR) measurements to evaluate the amounts of both fine-grained particles (fines) and moisture present in railway ballast. Changes to the bulk ballast electromagnetic (EM) properties in turn affect GPR wave travel times

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Surface wave testing for characterization of ballast and

Monitoring and identifying the changes in mechanical properties of ballast and foundation soil in a track system are essential to schedule and predict maintenance costs and to improve safety. Unlike qualitative measurements with the electromagnetic waves, for example, Ground Penetrating Radar, wave velocity measurements provide an opportunity

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IET Digital Library: Characterisation of ballast materials

In recent years the use of high frequency GPR antennas such as the 2GHz horn antenna have become popular for railway trackbed evaluation due to their ability to help determine the extent of fouling within the ballast layer. Fouling of the ballast affects both its strength and drainage properties. The theory is based on the scattering behaviour of GPR signals in an inhomogeneous media

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Research on Railroad Ballast Specification and Evaluation

Research on Railroad Ballast Specification and Evaluation GERALD P. RAYMOND rock, slag, and gravel railway ballast sources are summarized in this paper. Comments are included about the new Canadian Pacific Rail ballast specif i­ These two properties, texture and composition, are

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Track Ballast Fouling and Permeability Characterization by

Jan 01, 2014· Research off-campus without worrying about access issues. and Selig, E. T. Development of Material Properties for Railway Application of Ground Penetrating Radar. Proc., SPIE Ninth International and Tinjum, J. M. Detection of Fouling in Ballast by Electromagnetic Surveying. Proc., Annual Conference and Exposition, American Railway

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Geotechnical properties of ballast and Research Online

ballast deformation and degradation under different con-ditions. A flowchart of the experimental programme, conducted by the authors on railway ballast based on large-scale triaxial testing, is shown in Fig. 1. Ballast behaviour. Ballast is a free-draining granular material used as a load-bearing material in railway tracks. It is composed of

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Railroad Ballast Evaluation Using Ground-Penetrating Radar

The early detection of ballast fouling is of utmost importance to the safety of the rail system and its life-cycle cost-effectiveness. Ground-penetrating radar (GPR), a nondestructive evaluation tool, has shown its potential as a means of assessing the condition of the railroad

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[PDF] ASSESSMENT OF RAILWAY TRACK SUBSTRUCTURE

Ground penetrating radar (GPR) has been employed to assess railway track substructure (ballast, subballast, and subgrade) conditions. GPR involves transmitting radar pulses into the substructure and measuring return signals that have reflected off boundaries between substructure layers with different electromagnetic properties. The principle electromagnetic property of the layers is the

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Evaluating the Influence of Breakdown Fouling and Moisture

A complete study was performed to develop correlations between electromagnetic and mechanical properties of ballast. These correla tions can be used to predict the deformation properties of ballast and also its dynamic behavior under heavy axle load in

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Open Foundation-西南交通大学牵引动力国家重点实验室

Study on Dynamic Mechanical Properties of High-Speed Railway Ballast Cement and Mechanism of Ballast Cement. 11. Elkin Ferney Rodrigu. Federal University of Rio de Janeiro. Research on Multifunctional and High-Precision Test Bench for HTS Maglev System and Magnetic Bearing. 12. Frank N. Werfel. Adelwitz Technologiezentrum GmbH

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Evaluating the sensitivity of low-frequency ground

It was through the electromagnetic properties that the volumetric amount of fines and moisture present within the ballast and the type of subballast material were altered. The ground-penetrating radar response of each model was simulated using a finite-difference time-domain solver for Maxwell’s equations (gprMax).

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Analysis of the Dynamic Wheel Loads in Railway Transition

Abstract: Transition zones in railway tracks are the locations with considerable changes in vertical support structures, e.g., near bridges. Due to possible water flow constrictions in transition zone structures, there is frequently an increased moisture level in the ballast/subballast layers, which is a potential source of track degradation.

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Model track studies on fouled ballast using ground

Research highlights Identification of degree and types of fouling using MASW and GPR. The shear wave velocity (SWV) of clean and fouled ballast are measured. The SWV of fouled increases initially, reaches optimum and decreases. Optimum and Critical fouling point is defined for coal and sandy clay fouling. It is found that the 800 MHz ground coupled antenna gives better results.

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Subsurface Evaluation of Railway Track Using Ground

This report details the implementation of 2 GHz horn antennas for measuring working ballast thickness using ground penetrating radar and the initial implementation of a 500 MHz horn antenna used for subballast and subgrade characterization. The work was performed as part of the first task order and modification task 1 in the fourth phase of a multi-phase ground penetrating radar research and

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