The effect of subsurface mining on the land surface and preliminary calculation of pillars

In Estonia oil shale is produced by underground and surface mining. The technologies used exert a substantially different effect on the topography and water regime. The cavities generated by subsurface mining may lead to a series of deformations that travel to the land surface and hamper further use of mined-out areas. Based on mathematical calculations, prognostication of ground subsidence in dependence of pillar sizes is attempted.