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| Titel |
A GPR-based simulation approach for the analysis of railway ballast |
| VerfasserIn |
Andrea Benedetto, Luca Bianchini Ciampoli, Fabio Tosti, Lara Pajewski, Amir M. Alani, Andreas Loizos, Andrea Umiliaco, Maria Giulia Brancadoro, Daniele Pirrone |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250136261
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| Publikation (Nr.) |
 EGU/EGU2016-17258.pdf |
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| Zusammenfassung |
| This study aims at proposing a model capable to assess the physical conditions of railway
ballast, in terms of percentage of fouling within the material, by analyzing its electromagnetic
response.
For the calibration of such a model, a laboratory set-up was implemented in order to
reproduce a real-scale railway environment. In more details, a 1.47 m long × 1.47 m wide ×
0.48 m high plexiglass formwork was laid over a metal sheet, to define a proper domain of
investigation. The formwork was then filled up with railway ballast, progressively fouled with
a fine-grained pollutant material, namely, an A4 soil type according to the ASSHTO soil
classification. At each step of fouling percentage, electromagnetic surveys were carried out
by employing several ground-penetrating radar (GPR) systems, in both ground-coupled and
air-coupled configurations.
On the other hand, the validation of the model was performed through a simulation-based
approach. In particular, the main physical and geometrical properties of each ballast-pollutant
configuration were reproduced by means of a random sequence absorption (RSA) approach.
For the representation of the shape of the solid matrix of the ballast, a relatively complex
geometry was here adopted. Finally, the developed geometries were processed by the
GprMax 2D numerical simulator, employing a finite-difference time domain (FDTD) model
capable of generating a synthetic GPR response for the several configurations analysed in
laboratory environment.
As result, the potential of the combined use of RSA and FDTD approaches is
demonstrated, and a model for characterizing such a complex coarse-grained heterogeneous
material is finally proposed.
Acknowledgement
The Authors thank COST, for funding the Action TU1208 "Civil Engineering
Applications of Ground Penetrating Radar." |
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