Study on occurrence mechanism and control technology of mining-induced strata pressure in shallow depth coal seams of valley region

In order to analyze the geological disaster occurrence mechanism and the interactions of the shallow depth seam mining at the surface mine and underground mine in a valley region, based on the shallow depth seam mining condition in a valley region of Chuancao Gedan Mine, a site measurement, 3D geological modeling, numerical simulation and theoretical analysis combined study method was applied to study the in-situ rock stress distribution features of the coal and rock strata under the valley terrain as well as the stress field of the overburden strata caused by the seam mining, the displacement field and the failure field distribution law. The study result showed that the in-situ rock stress distribution of the mining coal and rock strata in the shallow depth seam under the valley region was affected by the surface valley terrain. Also with the depth increased, the influence role of the surface valley would be decreased. The coal mining operation of the coal mining face in the shallow depth seam passed through the valley region could be divided to an upward mining stage, slope top mining stage and the downward mining stage. During the upward mining stage passed through the above valley area, a dynamic mine pressure bump accident would be occurred in the coal mining face and a ground landslide, subsidence and other geological disaster would be induced. Based on the control of the geological disasters occurred in the underground mine or at the mine surface ground during the shallow depth seam mining under the valley region, the relevant prevention and control technology was provided.