Study on Stress Distribution Features of Overburden Strata for Upward Mining in Steep Inclined Thin Seam

Abstract：In order to ensure the safety mining in the steep inclined thin seam,base on the deposit conditions and hydrological conditions of the steep inclined seam in South No.2 Mining Block of Longhu Mine,the dispersed element UDEC numerical calculation was applied to study the stress distribution features and failure law of the overburden strata under the condition of the upward mining in the steep inclined seam.The results showed that there were the stress increased zone at the front of the coal mining face and at the solid coal side of the upward mining in the steep inclined thin seam and the stress concentration would be increased in a parabolic and linear individually with the coal mining face pushed forward.The area above the goaf of the coal mining face in the steep inclined thin seam would be a stress reduced area.The connection of the main stress tracing lines could form a stress pressure released arch.The arch height and arch corner of the pressure released arch would be increased with the coal mining face pushing forward.The arch shape would be converted from a symmetrical arch to nonsymmetrical arch to flat arch with the coal mining face pushing forward.The shape of the pressure released arch could reflect the stress transmission relationship between the different strata of the overburden strata and would be closely related to the bedding location of the overburden strata.