Study On The Feasibility Of Narrowing The Protective Pillaring In The Fully Mechanized Mining Face Under The Aquifer

The thick about280m covered on the Jiegou coal mining coal mine and on the lower quaternary aquifer about30.4m containing, because the mining coal seam by directly on "quaternary aquifer" of coal mining, the safety production posed a threat.Through analysing data of Similar experiments and Computer numerical simulation calculation,Aim at1010face in the central of Jiegou coalmine,analyzing the watery characteristic of "4th aquifers"、engineering geological properties of the bedrock weathering zone、combination characteristic of coal seam, but its lithological character are high argillaceous,watery and permeability is badly,and runoff、supplies、drain condition is worse;The bedrock weathering zone belongs to the weak rock layer whose main ingredients is sandstone and mudstone,and theirs’main ingredients is kaolinite and illite;As the bedrock weathering zone was weathering the plastic increased,In the overlying sunconsolidated formation under the action of gravity was gradually compacted.The bedrock weathering zone loss the capacity of Store guide water,so it’s watery become weak,and the weathered rock、fissures of Store guide water become impermeable layer and the impermeable body.In additon,in the coal mining process, caused bythe strength of plasticity reducing of the weathered bedrock can be highly preventing Guide water fracture zones developing.Based on the field test of the height of "Two zone" and Computer numerical simulation calculation,analyzing the distribution of overburden rock moving characteristics of1010face in the central of Jiegou coalmine,Obtain that the height of caving zone is6.9m and the height of the watering fissures is25.3m in the mining face;Finally, this papers gain the reasonable and security program of retaining coal pillar.