Identification of a Randomly-Fluctuating Continuous Model of the Ballasted Track Based on Measurements at the Pass-By of High-Speed Trains

Abstract

In this paper a randomly-fluctuating continuous model of ballasted railway tracks is studied. The ballast layer is considered as a linear, continuous, heterogeneous medium. Its properties are modeled as a sample of a random field, with a characteristic fluctuating length close to the average size of a ballast grain. The parameters of this model (mean wave velocities and coefficient of variation in the ballast layer) have to be identified from open-field measurements of the vertical acceleration in a ballasted railway track. The identification is performed for the mean model of the ballast and first steps in the identification process for the fluctuations are introduced. The geometry of the track (soil, ballast and sleepers) follows the real geometry where the experimental campaign was conducted.