SECURITY EVALUATION OF COAL MINING ABOVE THE CONFINED AQUIFERS

The key of the coal mining above confined aquifers is to understand the water-resistion ability of the coal seam floor.Many actors have influence on water inrush from the floor,of them the geological conditions of the floor are the most important.The "down-three-zone"theory provides theoretical foundation for security evaluation.Based on that this paper presents a set of methods and technology to evaluate security of the coal mining above the confined aquifers.