Numerical Simulation on pressure behavior of mining field under the conditions of hard roof

Taking the 33208 face of Xuandong 2# mine of Zhangjiakou mining group belonged to Jizhong energy group as project background, pressure behaviors of mining field under the conditions of hard roof when the coal is mined is studied by numerical simulation software of FLAC3D. The results show: because of hard roof the deformation law of the overburden showed as gradually decreasing trend when the distance is gradually increased between strata and coal seam, and strata separation phenomenon is obviously. Distinction of curved roof subsidence zone, the stress concentration zone in front of coal wall and the zone by re-compacted by ground pressure is not obvious, and collapse of immediate roof is difficultly. It is very complex of the stress field evolution in roof because it is affected by hard roof the zone that the stress is increased is not obvious, but the zone that the stress is decreased is obvious along the direction of face advance, and the roof weighting speed of goaf is small. The possibility of mine dynamic phenomena occurrence is increased because of hard roof.