Numerical Simulation of Overburden Strata Failure Law in Fully Mechanized Top Coal Caving Mining in Slices of Ultra Thick Seam

Base on the development height data of the water flow fractured zone measured in the fully mechanized top coal caving mining face of Huating Chenjiagou Mine,the FLAC3D inverse calculation was applied to simulate the overburden strata failure law of the seam caused by the fully mechanized top coal caving mining in the slice of the seam.The simulation data and the measured data were compared and analyzed.After the fully mechanized top coal caving mining in the slice of the seam,the failure and deformation of the overburden strata would form type loading structure and the pressure stress of the arch legs would be highly concentrated.The development pattern of the water flow fractured zone would be also as and could be well fitted with the actual detected height.The displacement field and stress field of the overburden strata and the distribution law of the plastic failure zone during the mining process were analyzed.