Question

UNDERGROUND MINING METHODS Underground mining methods Pillar supported Artifically supported Unsupported Room-andlongholestoping Sublevel and Bench-and-fill Cut-and-fill Shrink stoping VCR stoping Longwall Sublevel caving Block caving pillar stoping open stoping magnitudes of displacements in country rock strain energy storage in near-field rock Rock mass response to mining

Answer 1

Long wall, room and pillar methods of mining can both be used for mining suitable underground coal seams. Long wall has better resource recovery (about 80% compared with room & pillar method). Long wall mining is a form of underground mining where a long wall of wall is mined in a single slice (0.6 - 1.0 m thick) The long wall panel (block of wall that is being mind) is typically 3 - 4 km long &250 - 400 m wide Geotechnical engineering is one of the tools that the mining industry is encouraged to apply in the continuing endeavour to achieve safe, cost effective mines. The requirement to rehabilitate extensive area of a mine due primarily to failure to address the prevailing geotechnical issues, exposes the workforce to potentially hazardous ground conditions. Planes of weakness divide the mass upto a collection of potential blocks the size, shape and of which strongly influence rock ability conditions in underground mines.