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electromagnetic properties railway ballast research

Electromagnetic properties of railway ballast Request PDF

Request PDF Electromagnetic properties of railway ballast Laboratory experiments were undertaken to identify and characterise the dielectric properties of railway track ballast using Ground

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Electromagnetic properties of railway ballast ScienceDirect

Jul 01, 2001 1. To investigate whether the condition of the railway ballast can be classified by the dielectric constant, εr, — 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.

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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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(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] 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.

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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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M.R. Clark's research works The University of Edinburgh

Electromagnetic properties of railway ballast. Laboratory experiments were undertaken to identify and characterise the dielectric properties of railway track ballast using Ground Penetrating

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Railroad Ballast Evaluation Using Ground-Penetrating Radar

Jack and Jackson used 450- and 900-MHz GPR antennae to provide the image attributes of the ballast and subgrade (1). A fixed electromagnetic (EM) velocity of 5.1 × 108in./s (1.3 × 108m/s) was used in the study to estimate the thickness of a ballast layer.

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

The set-up was then investigated using different multi-frequency GPR horn antenna systems. The effects of the different physical conditions of ballast on the electromagnetic response of the...

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Introduction to Railroad Track Structural Design

• Ballast quality and ability to resist crushing forces (ballast degradation is the number 1 cause of ballast fouling) Some railroads use different track modulus (u) values in design. For example, Spring u may be used for rail bending and ballast depth, but Winter u used for rail seat forces. Other railroads may use a

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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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Railway Ballast Monitoring by GPR: A Test Site

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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An Entropy-Based Analysis of GPR Data for the Assessment

Railway ballast can be within the railway track bed and the inhomogeneities within the materials with different EM properties The frequency-based research has been focused on the spectral analysis of the GPR signals. Leng and Al-Qadi [24] used the Short-Time Fourier

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M.R. Clark's research works The University of Edinburgh

Electromagnetic properties of railway ballast. Laboratory experiments were undertaken to identify and characterise the dielectric properties of railway track ballast using Ground Penetrating

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“Test-site operations for the health monitoring of railway

Jan 01, 2020 Main electromagnetic parameters of railway ballast were estimated for each scenario using time- and frequency-domain signal processing techniques. Interpretation of the preliminary results has shown viability of the GPR method in detecting signs of decay at the network scale, thereby proving this technique to be worthy for implementation in

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[PDF] A simulation-based approach for railway applications

In this work a numerical model capable to predict the electromagnetic response of railway ballast aggregates under different physical conditions has been calibrated and validated by a simulation-based approach. The ballast model is based on the main physical and geometrical properties of its constituent material and it is generated by means of a random-sequential absorption (RSA) approach.

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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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Railway track settlements a literature review

2. Railway ballast 6 2.1 Ballast materials, requirements and properties 6 2.2 Experimental measurements on ballast 7 2.3 Ballast modelling 8 3. Track settlement 9 3.1 Experimental measurements on track settlements 11 3.2 Track stiffness measurements 12 3.3 Modelling ballast and track settlements 14 4.

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7901 SAICE Journal of Civil Engineering Vol 55 No 3

ballast fouling, earthworks INTRODUCTION The aim of a railway substructure investiga-tion is to characterise the track substructure based on its geotechnical properties. Care should be taken when conducting a substructure investigation to establish the correct remedial action (Brough et al 2003). Traditionally, for a typical rail line investiga-

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Introduction to Railroad Track Structural Design

• Ballast quality and ability to resist crushing forces (ballast degradation is the number 1 cause of ballast fouling) Some railroads use different track modulus (u) values in design. For example, Spring u may be used for rail bending and ballast depth, but Winter u used for rail seat forces. Other railroads may use a

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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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Assessment of layer thickness and uniformity in railway

radiation of very short electromagnetic impulses (< 10 ns) that are reflected at interfaces of materials with different dielectric properties (Figure 1). Figure 1 Working principle of georadar in reflection mode and resultant radargram. Assessment of layer thickness and uniformity in railway embankments with Ground Penetrating Radar

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Railway Ballast Fouling Detection Using GPR Data

ABSTRACT Ground‐penetrating radar has been recently used for quantifying railway ballast fouling conditions. This paper discusses two approaches for processing the railway ballast ground‐penetrating radar signal: the discrete wavelet transform method and the short‐time Fourier transform method. Ground‐penetrating radar field data collected in Wyoming in 2007 by two 2‐GHz air

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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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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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Track Ballast Fouling and Permeability Characterization by

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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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

get price

Railway Ballast Fouling Detection Using GPR Data

ABSTRACT Ground‐penetrating radar has been recently used for quantifying railway ballast fouling conditions. This paper discusses two approaches for processing the railway ballast ground‐penetrating radar signal: the discrete wavelet transform method and the short‐time Fourier transform method. Ground‐penetrating radar field data collected in Wyoming in 2007 by two 2‐GHz air

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A spectral analysis of ground-penetrating radar data for

Sep 01, 2017 Overall, the GPR-based research on railway ballast can be classified into i) research based on the analysis of the signal response in the time domain and ii) research based on the analysis of the signal spectrum in the frequency domain. Download : Download high-res image (460KB) Download : Download full-size image; Fig. 1. Typical ballasted

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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

get price

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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Experimental study on dynamic properties of railway

May 20, 2016 In this study, for better shear locking between ballast and TDA particles and preserving the ballasted track drainage, the particle size distribution of TDA was chosen as the same as that of dolomite ballast according to standard ballast gradation of AREMA NO. 4 ().The specific gravity of dolomite ballast and TDA were measured as 13.4 and 5.66 kN/m 3, respectively, based on ASTM.

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Assessment of layer thickness and uniformity in railway

radiation of very short electromagnetic impulses (< 10 ns) that are reflected at interfaces of materials with different dielectric properties (Figure 1). Figure 1 Working principle of georadar in reflection mode and resultant radargram. Assessment of layer thickness and uniformity in railway embankments with Ground Penetrating Radar

get price

Introduction to Railroad Track Structural Design

• Ballast quality and ability to resist crushing forces (ballast degradation is the number 1 cause of ballast fouling) Some railroads use different track modulus (u) values in design. For example, Spring u may be used for rail bending and ballast depth, but Winter u used for rail seat forces. Other railroads may use a

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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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Evaluating degraded ballast and track geometry variability

ballast degradation levels on long-term trends in track geometry is also contrasted between segments of track founded on different subgrade materials. This research also investigates the spatial association between degraded ballast and prolonged or

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7901 SAICE Journal of Civil Engineering Vol 55 No 3

ballast fouling, earthworks INTRODUCTION The aim of a railway substructure investiga-tion is to characterise the track substructure based on its geotechnical properties. Care should be taken when conducting a substructure investigation to establish the correct remedial action (Brough et al 2003). Traditionally, for a typical rail line investiga-

get price

Bibliography of FRA Office of Research and Development

42 anthology of rail dynami~s research. 96 assessment of locomotive crew in-cab occupational noise exposure. 13 ballast and subgrade requirements study: railroad track substructure design and performance practices. 13 ballast and subgrade requirements study: railroad track

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