Stochastic heterogeneous material modeling for wave propagation in a ballast layer Lúcio de Abreu Corrêa, Régis Cottereau, Charles Voivret, Sofia Costa D’Aguiar, Estelle Bongini and Baldrick Faure EPJ Web Conf., 140 (2017) 11012 Published online: 30 June 2017 DOI: 10.1051/epjconf/201714011012