Mining techniques and engineering application for “Coal-Water” dual-resources mine

Due to the reverse distribution of coal and water resources in Eastern China and Western China,the mining techniques and methods were proposed based on the concept of mining for “ Coal-Water” dual-resources mine,which elaborated optimization of mining method,parameters and mining technology,optimization and combination of multini- ty,underground separation discharge of clean water and sewage,intervention of hydrogeological condition,filling min- ing based on the specific filling-water hydrogeological conditions of main mineable coal seam in order to address the problem of security and green development on coal resources,the supply of water resources,the sharp contradictions and conflicts between ecological balance and environmental protection;and realize the targets on controlling and pro- tecting water inrush,the protection and utilization of water resources,and the improvement of ecological environment. A case study in Xingyuan coal mine of Yuxian mining area was carried out and analyzed. The mining method for the coal seam under the unconsolidated aquifer with thin bedrock and the mechanical model of clamped beam were estab- lished,and the author presented the design method of coal pillar based on the yielding theory and amended the calcu- lation formula of load overlying coal pillar. The results show that the key to the yielding pillar design is the existence of main key stratum and formation of stable expansion pressure,and the strata weight under expanding pressure arch was supported by the yielding pillar with enough strength. The safety coefficient is larger under the following three condi- tions:room 5 m,while pillar 4 m;room 5 m,while pillar 5 m;and room 6 m,while pillar 5 m.