Abstract: A method of analyzing influencing factors of a contribution rate of elastic energy of a top plate during catastrophe of a coal body; the specific steps are: taking a core on site and processing the core into a standard test piece; obtaining, by means of an indoor mechanical test, elastic moduli of the top plate and of gas-containing coal, respectively; substituting the obtained elastic moduli and thicknesses of the top plate and of the gas-containing coal into a calculation formula so as to obtain the contribution rate of the elastic energy of the top plate; and analyzing the influence of the contribution rate of the elastic energy of the top plate in the two situations of configuring the same thickness ratio and a different elastic modulus ratio and the same elastic modulus ratio and a different thickness ratio. The method has important theoretical significance and practical engineering value.

Abstract: The present disclosure discloses a method for estimating a contribution rate of elastic energy of a top plate during instability catastrophe of a deep gas-containing coal body, which specifically includes the following steps: acquiring gas pressure of a coal seam; acquiring a thickness of the coal seam and the top plate according to a borehole histogram; coring in the field, processing and pre-processing coal samples, and acquiring an elastic modulus of the top plate, gas-containing coal and standard specimens of a gas-containing coal-rock combination through indoor mechanical tests, respectively; deducing contribution of the elastic energy of the top plate with the help of a graphic area for a stress-strain curve, and obtaining a quantitative expression of the contribution rate of the elastic energy of the top plate based on the elastic modulus and the thickness of the top plate and the gas-containing coal.

Abstract: A method of analyzing influencing factors of a contribution rate of elastic energy of a top plate during catastrophe of a coal body; the specific steps are: obtaining coal seam gas pressure; according to a drilling histogram, obtaining coal seam thickness and top plate thickness; taking a core on site and processing the core into a standard test piece; obtaining, by means of an indoor mechanical test, elastic moduli of the top plate and of gas-containing coal, respectively; substituting the obtained elastic moduli and thicknesses of the top plate and of the gas-containing coal into a calculation formula so as to obtain the contribution rate of the elastic energy of the top plate; and analyzing the influence of the contribution rate of the elastic energy of the top plate in the two situations of configuring the same thickness ratio and a different elastic modulus ratio and the same elastic modulus ratio and a different thickness ratio.

Abstract: The present disclosure discloses a method for estimating a contribution rate of elastic energy of a top plate during instability catastrophe of a deep gas-containing coal body, which specifically includes the following steps: acquiring gas pressure of a coal seam; acquiring a thickness of the coal seam and the top plate according to a borehole histogram; coring in the field, processing and pre-processing coal samples, and acquiring an elastic modulus of the top plate, gas-containing coal and standard specimens of a gas-containing coal-rock combination through indoor mechanical tests, respectively; deducing contribution of the elastic energy of the top plate with the help of a graphic area for a stress-strain curve, and obtaining a quantitative expression of the contribution rate of the elastic energy of the top plate based on the elastic modulus and the thickness of the top plate and the gas-containing coal.

Abstract: A ground wellhole dedicated protective pipe, disposed inside a ground wellhole for gas extraction of a mining-induced area, includes a casing, and a chain inside the casing and slidable relative to the casing. The chain includes a chain formed by a plurality of chain drums through serial connection, and a detachable connecting piece connecting between chains. A plurality of air holes is opened in the chain drum along an axial direction of the chain drum.

Abstract: Disclosed is a ground wellhole dedicated protective pipe for gas extraction of a mining-induced area. The ground wellhole dedicated protective pipe for gas extraction of a mining-induced area is disposed inside a ground wellhole for gas extraction of the mining-induced area and the ground wellhole dedicated protective pipe for gas extraction of a mining-induced area includes a casing and a chain that is disposed inside the casing and slidable relative to the casing, wherein the chain includes a plurality of chain drums and connecting pieces movably connecting the adjacent chain drums, and a plurality of air holes are opened in the chain drum along an axial direction of the chain drum.