Study On The Damage Mechanism Of Coal Mining On Groundwater Resources And Its Protection Countermeasures

Based on the present situation of serious water scarcity and groundwater resources waste and pollution induced by mine water massive discharge in our country's coal mine area, this paper studies the damage mechanism of coal mining on groundwater resources by using the method of field investigation, theoretical analysis and numerical simulation; Moreover puts forward the protection countermeasures of groundwater resources in coal mining process.With the strata pressure control theory, mining rock mass structure theory, elasticity theory, damage mechanics and fracture mechanics theory as a guide, the paper theoretically studies the damage mechanism of coal mining activities on the coal seam roof and floor aquifer, and discusses the influence factors and determination method of the height of overlying strata water flowing fractured zone and the depth of destroyed floor.Based on the specific geological and mining condition of Huafeng coal mine No.1409 working face, the paper simulates the process of the mining-induced fractures'development and the transfixion to the roof and floor aquifer with the rock failure process fluid-solid coupling analysis system RFPA2D-Flow, and studies the development characteristics of water flowing fractured zone and variation of surrounding rock's permeability.Combined with the situation of mining and mine water discharge, the paper analyzes the influence of mining on the coal field's conglomerate aquifer, coal measure strata aquifer, Xujiazhuang limestone aquifer and Ordovician limestone aquifer. Then analyzes and evaluates the influence of coal mining activities on the groundwater environment.This paper studies the partial mining, backfill mining and other coal mining method with groundwater resources protection; and proposes some measures to protect groundwater resources, such as retaining reasonable waterproof coal pillar and grouting reconstruction technology of footwall stratum. Finally puts forward a suggestion of the resource utilization of mine drainage.