Study On The Water Resistance Of Fault Waterproof Coal Pillar And Coal Seam Floor In Deep Mining

At present,the development of coal resources in China has entered the stage of deep mining.With the increase of mining depth,under the mining background of high mine pressure,high water pressure and the decrease of effective thickness of water resisting layer,the situation of safety production in coal mine tends to be severe,and coal mine enterprises will face the double pressure problems of floor water disaster prevention and economic growth.A large number of water inrush cases show that the majority of water inrush from coal seam floor is caused by faults.Under the background of regional management in mining area,the reliability of fault waterproof coal pillar and the water resistance of coal seam floor are still the main problems faced by the prevention and control of water in deep mining.Based on the technical route of in-situ test and computer simulation,this paper discusses two key scientific problems:the reasonable setting of fault waterproof coal pillar and the water resistance of floor.The in-situ test results show that the tensile strength of the coal seam is close to the current value,and the tensile strength of the floor is greater than the current value.The results show that:The tensile strength of 2~#coal seam in Fengfeng mining area is 0.5MPa,and the tensile strength of coal seam floor is 0.8MPa,which decreases near the fault zone;The method of water inrush coefficient is still suitable for determining the width of fault waterproof coal pillar in deep mining and the width of fault waterproof coal pillar has a certain linear relationship with mining depth;The pressure of confined water decreases gradually in the process of leading up along the fault zone,and the water pressure of the waterproof coal pillar is smaller than that of the coal seam floor aquifer;The width of waterproof coal pillar calculated by water inrush coefficient method is too large,according to the characteristics of gradual attenuation of water pressure in the process of confined water leading up along the fault zone,an improved water inrush coefficient method is proposed to retain the waterproof coal pillar of the fault;In the context of regional governance of mining area,the water resistance of 2~#coal seam floor aquifer is strong,and that of 4~#coal seam floor aquifer is weak.