Evaluation of Track Substructure Thickness Design via Geo-reinforcement Techniques

摘要

Railway engineering has rapidly evolved to accommodate higher speed and heavier transport loads in a timely fashion. This trend brings attention for railroad engineers to come up with an effective track structure design that minimizes frequent maintenance activities and prolongs service lives. In this study, the effectiveness of geo-reinforcement techniques for track substructure enhancement such as cement treated subballast, asphalt subballast, and application of geosynthetics is evaluated via a limited numerical analysis in terms of thickness design that related to material savings. For the evaluation of track substructure thickness design, a threshold stress approach is employed that gauges tie-ballast contact stress and vertical stress at the top of subgrade layer. It is envisioned that the application of geo-reinforcement for track substructure appears to be effective in improving the load bearing capacity that results in reduced substructure thickness. Further studies need to be conducted to develop a logical mechanistic railroad design procedure to account for use of various types of reinforcement methods.