Dynamic disasters,such as rock burst due to the breaking of large area stiff roof strata,are known to occur in the hard rock strata of coal mines.In this paper,mechanical models of the fracturing processes of thick ha...Dynamic disasters,such as rock burst due to the breaking of large area stiff roof strata,are known to occur in the hard rock strata of coal mines.In this paper,mechanical models of the fracturing processes of thick hard rock strata were established based on the thick plate theory and numerical simulations.The results demonstrated that,based on the fracture characteristics of the thick hard rock strata,four fracture models could be analyzed in detail,and the corresponding theoretical failure criteria were determined in detail.In addition,the influence of weak interlayer position on the fracture models and ground pressure of rock strata is deeply analyzed,and six numerical simulation schemes have been implemented.The results showed that the working face pressure caused by the independent movement of the lower layer is relatively low.The different fracture type of the thick hard rock strata had different demands on the working resistance of the hydraulic powered supports.The working resistance of the hydraulic powered supports required by the stratified movements was lower than that of the non-stratified movements.展开更多
The top-coal falling ability is a key factor to analyze for the application of coal mining with top-coal caving. Based on a hard-and-thick strata,which acts both as the floor of the upper coal seam and as the roof of ...The top-coal falling ability is a key factor to analyze for the application of coal mining with top-coal caving. Based on a hard-and-thick strata,which acts both as the floor of the upper coal seam and as the roof of the lower coal seam, nine mining projects were put forward to examine the mining of upper and lower coal seams, and a numerical simulation was used to study in detail the corresponding top-coal compressed volume of the lower coal seam. By the simulation effects of different layouts of coalface, the rational mining method was determined to be the staggered layout of coalface in the upper and the lower coal seam. This can ensure the successful use of fully-mechanized coalface with top–coal caving in the lower coal seam.展开更多
基金the Beijing Outstanding Young Scientist Program of China(No.BJJWZYJH01201911413037)projects(Nos.41877257 and 51622404)supported by National Natural Science Foundation of China+1 种基金Shaanxi Coal Group Key Project of China(No.2018SMHKJ-A-J-03)the Fundamental Research Funds for the Central Universities of China(No.2021YJSLJ23)。
文摘Dynamic disasters,such as rock burst due to the breaking of large area stiff roof strata,are known to occur in the hard rock strata of coal mines.In this paper,mechanical models of the fracturing processes of thick hard rock strata were established based on the thick plate theory and numerical simulations.The results demonstrated that,based on the fracture characteristics of the thick hard rock strata,four fracture models could be analyzed in detail,and the corresponding theoretical failure criteria were determined in detail.In addition,the influence of weak interlayer position on the fracture models and ground pressure of rock strata is deeply analyzed,and six numerical simulation schemes have been implemented.The results showed that the working face pressure caused by the independent movement of the lower layer is relatively low.The different fracture type of the thick hard rock strata had different demands on the working resistance of the hydraulic powered supports.The working resistance of the hydraulic powered supports required by the stratified movements was lower than that of the non-stratified movements.
基金Projects 50374065 supported by National Natural Science Foundation of China
文摘The top-coal falling ability is a key factor to analyze for the application of coal mining with top-coal caving. Based on a hard-and-thick strata,which acts both as the floor of the upper coal seam and as the roof of the lower coal seam, nine mining projects were put forward to examine the mining of upper and lower coal seams, and a numerical simulation was used to study in detail the corresponding top-coal compressed volume of the lower coal seam. By the simulation effects of different layouts of coalface, the rational mining method was determined to be the staggered layout of coalface in the upper and the lower coal seam. This can ensure the successful use of fully-mechanized coalface with top–coal caving in the lower coal seam.