Analyzing falling crack failure of overburden strata of shallow coal seam and its control method

The mining under the condition of the shallow coal seam,the thick loose beds and the thin base rock in Shendong mining area in Shaanxi Province of China,causes the surface subsidence take on the situation of the discontinuous falling crack failure.A great deal of analysis and research indicates that the crack damage is controlled by the key stratum in the overburden strata.Therefore, the key for solving the control of mining damage under this condition is to research the rules of the key stratum failure and the sliding condition in the shallow seam.Taking No.1203 longwall face in Daliuta mine of Shendong mining area for example,the paper presents the relationship between the stability condition of the key stratum structure and the mining damage with the method of analyzing theory and numerical simulation,supplying the theoretic evidence for the environmental protection and the confirmation of the reasonable and economical control mining methods in Shendong mining area.