Nano-composite coated jute geotextile for enhanced stability and environmental benefits in coal overburden dump management

India's rising energy needs have expanded opencast coal mining, leading to significant overburden (OB) accumulation. Effective management of OB dumps requires addressing critical challenges, including slope instability influenced by seismic activity, as well as land use constraints and environmental considerations. This study investigates the use of nano-composite coated jute geotextile (NCCJGT) to reinforce OB dump slopes and enhance stability under pseudo-static earthquake conditions. The NCCJGT, coated with polymer and nano-fillers, improved jute geotextile tensile strength by 55.7% in the machine direction (MD) and 51.0% in the cross-machine direction (XMD). The biodegradation analysis revealed that after six months of exposure to harsh conditions, NCCJGT retained 88.6% of its tensile strength in the MD and 91.23% in the XMD, whereas untreated JGT completely degraded. Numerical modeling through Slide 3 of Rocscience Inc. further demonstrated that NCCJGT reinforcement improved the factor of safety (FoS) by 6.05%, 7.89%, and 9.70% for slopes of 30 m, 35 m, and 40 m heights, respectively, under earthquake loading conditions simulated through pseudo-static analysis. Optimizing slope geometry by increasing lift heights to 35 m and 40 m added 0.30 Mm3 and 0.36 Mm3 capacity, saving 12 hectares and 18 hectares of land, respectively. Construction costs decreased by 2.36% and 6.63% for 35 m and 40 m reinforced slopes. NCCJGT, as a biodegradable, eco-friendly alternative to synthetic geotextiles, reduces microplastic pollution, supports vegetation growth, improves soil stability, and ensures long-term ecological stability. These findings position NCCJGT as a sustainable solution for stabilizing OB dumps, improving spatial efficiency, and reducing environmental impact in opencast mining.