A computer-aided model for the simulation of railway ballast by random sequential adsorption process

This paper presents a computer-aided multi-stage methodology for the simulation of railway ballasts using the Random Sequential Adsorption (RSA ? 2D domain) paradigm. The primary stage in this endeavour 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 visualised in the Computer-Aided Design (CAD) environment. The outcomes of the simulation are analysed 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) non-destructive 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 modelling for the assessment of railway ballast conditions.