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Keywords: ballast pick-up, high-speed trains, experiments on railway track, train interoperability, standardization.

Summary

One of the phenomena that limits the velocity of trains on high speed lines is the so-called "ballast pick-up". It is a ballast train-induced-wind erosion (BATIWE) that can produce damage to the train underbody and the infrastructure surrounding the tracks.

The train-ballast interaction can be split into two parts: one that only depends on the aerodynamics and not on the ballast mass and inertia properties, and the other one which is the capability of the ballast to withstand the mechanical action of the wind, which depends on its mass and inertia properties.

Some investigations have shown that the effect on the track of a given train can be identified as a kind of signature, which can be obtained by averaging the measurements taken during several passes of the train.

The analysis of the measurements also allows for a criterion of ballast flight initiation to be obtained. It is based on the idea that the first rotation of a ballast stone occurs when the impulse given to the stone (arising from the aerodynamic loading produced by the wind gust generated by the passing train) overpasses a given impulse, or critical impulse. This critical impulse depends on the physical properties of the stone (mass, shape, moment of inertia, etc.) and its position on the track bed.

The aim of this contribution is to report on the experimental results obtained in the ADIF'S Brihuega (Guadalajara) test station, on the Madrid to Barcelona high speed line, and the way they can be used to support the feasibility of the definition of a criterion to evaluate the BATIWE capability of trains. A data post-process method has been developed, considering the number of passes enough for the results to achieve statistical relevance.

In order to help in the practical application of this criterion, the method has been applied to two different trains and two different tracks (different levels of the ballast bed with regard to the level of the rail base). The results obtained show the feasibility of the proposed method, and contribute to a method of BATIWE characterization, which can be relevant for the development of train interoperability standardization.

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Front Page Browse CCP CSETS CTR IJRT Other Authors Search Purchase Guide FAQ Contact us	Civil-Comp Proceedings ISSN 1759-3433 CCP: 98 PROCEEDINGS OF THE FIRST INTERNATIONAL CONFERENCE ON RAILWAY TECHNOLOGY: RESEARCH, DEVELOPMENT AND MAINTENANCE Edited by: J. Pombo Paper 103 Criteria for Ballast Flight Initiation Induced by High Speed Trains F. Sorribes¹, F. Navarro-Medina¹, A. Sanz-Andrés¹, I. Perez-Grande¹, A. Martínez¹, E. Vega¹, A. Mascaraque², M. Rodriguez-Plaza², I.J. Iglesias Díaz², A. Andres-Alguacil² and D. Alonso Gimeno² ¹IDR/UPM, E.T.S.I. Aeronáuticos, Universidad Politécnica de Madrid, Spain ²ADIF, Technological Innovation Direction, Administrador de Infraestructuras Ferroviarias, Madrid, Spain doi:10.4203/ccp.98.103 purchase the full-text of this paper Full Bibliographic Reference for this paper , "Criteria for Ballast Flight Initiation Induced by High Speed Trains", in J. Pombo, (Editor), "Proceedings of the First International Conference on Railway Technology: Research, Development and Maintenance", Civil-Comp Press, Stirlingshire, UK, Paper 103, 2012. doi:10.4203/ccp.98.103 Keywords: ballast pick-up, high-speed trains, experiments on railway track, train interoperability, standardization. Summary One of the phenomena that limits the velocity of trains on high speed lines is the so-called "ballast pick-up". It is a ballast train-induced-wind erosion (BATIWE) that can produce damage to the train underbody and the infrastructure surrounding the tracks. The train-ballast interaction can be split into two parts: one that only depends on the aerodynamics and not on the ballast mass and inertia properties, and the other one which is the capability of the ballast to withstand the mechanical action of the wind, which depends on its mass and inertia properties. Some investigations have shown that the effect on the track of a given train can be identified as a kind of signature, which can be obtained by averaging the measurements taken during several passes of the train. The analysis of the measurements also allows for a criterion of ballast flight initiation to be obtained. It is based on the idea that the first rotation of a ballast stone occurs when the impulse given to the stone (arising from the aerodynamic loading produced by the wind gust generated by the passing train) overpasses a given impulse, or critical impulse. This critical impulse depends on the physical properties of the stone (mass, shape, moment of inertia, etc.) and its position on the track bed. The aim of this contribution is to report on the experimental results obtained in the ADIF'S Brihuega (Guadalajara) test station, on the Madrid to Barcelona high speed line, and the way they can be used to support the feasibility of the definition of a criterion to evaluate the BATIWE capability of trains. A data post-process method has been developed, considering the number of passes enough for the results to achieve statistical relevance. In order to help in the practical application of this criterion, the method has been applied to two different trains and two different tracks (different levels of the ballast bed with regard to the level of the rail base). The results obtained show the feasibility of the proposed method, and contribute to a method of BATIWE characterization, which can be relevant for the development of train interoperability standardization. purchase the full-text of this paper (price £20) go to the previous paper go to the next paper return to the table of contents return to the book description purchase this book (price £110 +P&P)
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