Research On Roof Water Inrush Mechanics Of Shallow Seam

Based on the theoretical analysis,physical similarity simulation experiment and numerical simulation,this paper studies the stability and water barrier of the affected soil in the shallow coal seam by putting the Yushenfu mine area as the research background,which provides the basis for the coal mine water inrush prediction,and the research results have certain theoretical significance for the coal mine safety production.Based on the physical and mechanical properties and the water properties of the three-toothed horses,its properties were tested by using soil mechanics,which lays the foundation for further research on similar simulation and numerical simulation.The results show that the permeability of the three-toe horses is decreased with the increasing of the overburden load,and the permeability increases with the water head pressure.Taking the condition of shallow coal seam,thin bedrock and thick medium seam under the thick soil layer of Yushenfu Mine area as the object of study,the sinking and stratified stratum of the segregated soil layer are studied by the solid-liquid coupling simulation experiment.Due to the water pressure and the level of compression,part of the fracture is closed,the fracture of the fractured zone is more obvious because the hinge effect is not easy to be closed.The height of the hydraulic fracture zone is influenced by the key stratum,and the experiment shows that the higher the position of the key stratum,the lower of the developmental height of the fissure zone,and vice versa.Through the infrared imager,the movement of water is showed,it indicates that water movement in the rock layer is not only the vertical movement but also the horizontal movement,which is the performance of laminar motion.The thickness of the water protection soil layer of the overburden is different,and the effect of protection water is different.If the ratio of thickness of the soil layer to mining height k ? 4,the water protection layer will be irreversibly damaged,Under the condition of the ratio of thickness of the soil layer to mining height 4 <k <15,the fissures of the seawater will pass through and form the water inrush channel.However,with the continuous action of the working face,some fractures will heal under the combined action of horizontal force and water pressure.Under thecondition of the ratio of thickness of the soil layer to mining height k ? 15,fractures of the water protection soil layer will not penetrate the cracks,and it can not form a water inrush channel.Through FLAC3 D numerical simulation software,the displacement field,plastic failure area,pore water pressure and seepage of the surrounding rock under the influence of mining are analyzed,Through the analysis of the plastic zone,the pore water pressure cloud and the seepage field,it shows that the area is mainly concentrated in the open eye and face above the working face.The numerical simulation shows that the water inrush from the roof of the shallow coal seam is caused by the destruction of the seepage soil layer and the water conducting fracture zone passes through the the water protection soil layer and combining with aquifer.