A Computer-Aided Model for the Simulation of Railway Ballast by Random Sequential Adsorption Process

This article presents a computer-aided multistage methodology for the simulation of railway ballasts using the Random Sequential Adsorption (RSA – 2D domain) paradigm. The primary stage in this endeavor is the numerical generation of a synthetic sample by a “particle sizing and positioning” process followed by a “compaction” process. The synthetic samples of ballast are then visualized in the Computer-Aided Design (CAD) environment. The outcomes of the simulation are analyzed by comparison with the results of an experimental investigation carried out using a methacrylate container in which real samples of railway ballast are formed. A test of model reliability is carried out between the aggregates number and the grading curves of the synthetic sample and the real one. A validation is therefore performed using the ground-penetrating radar (GPR) nondestructive testing (NDT) method and the finite-difference time-domain (FDTD) simulation developed in a computer-aided environment. The results prove the viability and the applicability of the proposed modeling for the ssessment of railway ballast conditions.