Modeling Crosstie-Ballast Load Distribution in a Railroad Trackbed using a Linear-Elastic Analysis

This paper details a linear-elastic approach to modeling crosstie-ballast interfacial load distribution in a railroad timber crosstie trackbed using RISA 3D, a finite element modeling software. RISA results closely mirrored experimental findings with some slight deviation as discussed in the paper. The modeling methodology outlined here advances previous trackbed research at the University of Kentucky, U.S., and could be used in future trackbed finite element analyses for design or research in load path distribution and load magnitude predictability. This paper details the approach used to model a timber crosstie trackbed superstructure, including initial troubleshooting stages, and explains the derivation of program input variables. A sensitivity analysis performed on the main model determined the workable extent of linearity. The analysis also examined the effect of a poor/muddy trackbed support loading condition. The paper concludes with potential recommendations in relation to the work.