A Numerical Study on Geofoam Application in the Settlement Reduction of Railway Embankments

Construction of railway track embankment over a soft subgrade will bring the necessity of using soil improvement methods for bearing capacity and settlement criteria satisfaction. As a practical improvement method, railway embankment filled with geofoam blocks is studied in this paper. First a bilinear stress-strain model is developed in FLAC2D to simulate geofoam embankment behavioral model. Second, the stability of a specified height range of geofoam embankments under static and dynamic train surcharges is investigated. Finally parametric studies are executed to monitor the variation of track dynamic settlement due to embankments height, subgrade un-drained strengths (Cu) and train surcharge amplitude and velocity. Results are verified. Such parameters can significantly affect the track dynamic settlement. Using multivariable regression and least squared methods analytical equations are derived to quantify an estimation of track dynamic settlement based on participating parameters