A Reinforced Earth Railway Embankment for A Coal Handling Plant in Talchar, India: A Case Study

Construction of an embankment subjected to heavy static and dynamic loads using a low bearing local soil poses a great challenge for geotechnical designers. This case study provides information about the complexities encountered in design of a 24 m high and 120 m long trapezoidal embankment (made of locally available soil intermixed with mining material) having top and base width of 60 m and 145 m respectively at a coal handling plant in Talchar, India for transportation of materials through rail wagons. The embankment proposed to be built using locally available low bearing capacity soil was proposed to withstand loads from 3 railway tracks, two 50 m tall rapid loading system (RLS) towers and two supporting trestle towers collectively resting on 6 embedded raft foundations. To ensure both local and global stability of the embankment, the stabilization of the construction soil was done using an optimized configuration of geotextile, geogrids, geocells. For design of embankment, 3D numerical model was formulated using finite element software MIDAS GTS NX taking into account reinforcement configurations obtained through laboratory bearing tests. Stress and deformation contours of the unreinforced embankment were used to identify the failure zones, which guided the strategic placement of reinforcements. The revised analysis with geosynthetic reinforcements demonstrated a substantial enhancement in the load-bearing capacity of the embankment, bringing vertical settlements within acceptable limits. Additionally, remediation measures for slope stabilization using soil nails were proposed for future implementation in the event of potential failure due to unforeseen conditions.