Geotechnical Issues in Decommissioning Surface Lignite Mines—The Case of Amyntaion Mine in Greece

Recent changes in the fossil-fuel energy sector require coal mining industries to plan for future, including developing procedures decommissioning and closure associated with mines. In surface mining, geotechnical issues of include long-term stability pit slopes, particularly as is gradually filled water. This paper investigates such slope issues, emphasis on conditions prevailing Amyntaion lignite mine, Western Macedonia, Greece. Analytical numerical methods have been developed used estimate temporal evolution overall safety factor, water level rises, creating a lake. It shown that until lake reaches critical depth approximately 15–35% final equilibrium condition, factor against instability decreases slightly (by about 3% case study, up 5–10% other conditions) compared its value at end exploitation. At higher levels, increases significantly, beneficial effect pressure acting overcomes adverse pore rise inside slope. typical mines, achieved within few years, since area smaller deeper levels; thus, more favorable are usually reinstated years after mine closure, while small reduction during initial stages inconsequential. The parameters influencing magnitude short-term produces normalized graphs rises. results analyses can be preliminary studies