Page 315 - 360.revista de Alta Velocidad - Nº 5

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número 5 - junio - 2018. Pág 313 - 321

Development of an alternative maintenance technique for

railway ballasted tracks

Sol-Sánchez, Miguel

Moreno-Navarro, Fernando

Rubio-Gámez, Mª Carmen

University of Granada, Spain.
1

Abstract

Currently, ballast tamping is the most common maintenance intervention in
ballasted tracks in order to restore original geometry while recovering damping
capacity. However, it is wellknown the limited effectiveness of this technique
due to the degradation of ballast particles during tamping, and to the memory
phenomenon of ballast layer which quickly restores its pre-maintenance geometry.
Then, under the need for developing more durable and effective maintenance
techniques, this paper proposes an alternative process based on combining the
benefits of using Under-Sleeper Pads and the process known as Stoneblowing, by
replacing part of the small stones applied during this last technique with rubber
particles from wasted tires that act as flexible aggregates under the sleeper. For
this purpose, this paper presents an initial laboratory study focused on analysing
the viability and effectiveness of this alternative technique while defining the
influence of the quantity of rubber as main designing parameter. Results are based
on full-scale testing box tests, and they show that this process allows for reducing
short and long-term ballast settlement while reducing ballast degradation and the
stress transmitted to sub-layers, in comparison to conventional stoneblowing and
to the use of under-sleeper pads. Also, it is possible to optimize track deflection
and damping capacity by using different quantities of rubber.

Keywords: Stoneblowing, Under-sleeper pads, rubber particles, full-scale testing box, laboratory study.

1 Sol-Sánchez, Miguel. University of Granada. Email: msol@ugr.es (corresponding author)
Moreno-Navarro, Fernando. University of Granada. Email: fmoreno@ugr.es
Rubio-Gámez, Mª Carmen. University of Granada. Email: mcrubio@ugr.es

International Congress on High-speed Rail: Technologies and Long Term Impacts - Ciudad Real (Spain) - 25th anniversary Madrid-Sevilla corridor 313