Mechanical performance of MSE walls with coal mine overburden as backfill

This study offers insights on the possibility of using coal mine overburden as backfill material for the mechanically stabilised earth (MSE) wall through the physical model tests. The paper presents 1 g model tests of an MSE wall with three different geogrid spacings supporting a ballastless railway track, highlighting the change in stress distribution. The train loading was considered the primary destabilising force. For each geogrid spacing, five different loading conditions were considered by changing the axle load and speed of train. A reduced scale model of the MSE wall supporting ballastless railway track for high speed trains was constructed in a mild steel box of dimension 2 m × 2 m × 1.8 m. A computer controlled loading system was used to simulate the dynamic load due to the movement of the train. The results indicates that the load distributes uniformly for lesser spacing between the geogrids. The evaluated geotechnical properties of the material were found to be consistent with the requirements specified in most international guidelines for reinforced soil backfill. Furthermore, the measured track settlements and wall deformations were well within the maximum serviceability limits prescribed in relevant standards. The total wall deflection was less than 1.5 mm in all test cases.