Method for Determination of Supporting Resistance of Initial Compression Support in Shallow Buried Close-distance Coal Seam Group Mining

Abstract

The invention discloses a method for determining the support resistance of the support support for the initial compression of the roof in the mining of shallow-buried and close-distance coal seam groups. Through physical simulation research, it is found that when the working face of the lower coal seam is initially compressed (the interlayer overlying rock is broken for the first time), the key layer Breaking forms an "asymmetric three-hinge arch structure", and the load layer on the structure is the collapsed roof of the upper coal seam goaf. The caving roof structure of the upper coal seam is activated after the mining of the lower coal seam, and together with the three-hinge arch structure of the lower coal seam, an "asymmetrical three-hinge arch beam and arch shell load structure" is formed. By establishing the mechanical model of the beam anchored in the key layer of the coal seam under the shallow coal seam group, the calculation formula of the critical layer's ultimate collapse distance is revised, and the parameters of the roof structure block of the lower coal seam are determined. The calculation model of the support load for the initial pressure of coal seam mining under the close-distance coal seam group is established. Based on the action of dynamic and static loads, a reasonable method for determining the working resistance of the support for the initial pressure is proposed, which provides a theoretical basis for the control of the initial pressure of the roof in the mining of shallow buried coal seam groups.

Description

【Technical field】 [0001] The invention belongs to the technical field of coal mining, and relates to a method for determining the support resistance of a supporting support for the initial pressure of a shallow-buried and short-distance coal seam group mining roof. 【Background technique】 [0002] The Jurassic coalfield in northern Shaanxi is a super-large coal resource base in my country. The coal reserves in this area are large, the coal seams are buried shallowly, there are many mineable coal seams, and the mining conditions are relatively simple. However, as the mining scale of each mine in the coalfield increases year by year, the first coal seam in some areas has been mined, and the mining of the second and third main coal seams will begin. According to the production practice over the years, in the process of coal seam group mining, when the lower coal seam is mined, it is easy to appear abnormal pressure frame, coal wall slabs, two road bottom heaving volume increase,...

AI Technical Summary

Problems solved by technology

According to the production practice over the years, in the process of coal seam group mining, when the lower coal seam is mined, it is easy to have abnormal pressure, coal wall slabs, two road bottom heaving volume increase, roof collapse and other severe pressure phenomena, which not only seriously threaten the operators safety, and restrict the safe and efficient production of the mine

[0003] At present, the structural characteristics of the roof and the support load are determined by the roof structure characteristics of the single shallow coal seam mining for the first time in the coal seam mining under the shallow coal seam group, but the calculation process does not take into account the upper coal seam. The action characteristics of uneven load formed by mining, and the breaking law and characteristics of the roof under the action of uneven load are not considered

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