Through theoretical analysis, simulation test and practice, the law of a fracture'sinfluence on hard top coal press cracking was studied. The study focused on the relationbetween fracture and coal strength, top co...Through theoretical analysis, simulation test and practice, the law of a fracture'sinfluence on hard top coal press cracking was studied. The study focused on the relationbetween fracture and coal strength, top coal caving ability and work face layout. Based onthe investigation of the fracture system, the control of press cracking was achieved bymatching working face to fracture orientation to improve top-coal caving ability and recovery. The matching principle was pointed out: The top-coal caving working face should beperpendicular to or obliquely cross the primary fracture at a large angle, and cross thesecondary fracture at a small angle. The rational match can increase the recovery ratio oftop-coal and avoid rib spalling. The application of control technology on hard top coalpress cracking was introduced at the Iongwall top-coal caving face.展开更多
In order to explore the influence of different caving thicknesses on the MSS distributionand evolving characteristics of surrounding rocks in unsymmetrical disposal andfully mechanized top-coal caving (FMTC),based on ...In order to explore the influence of different caving thicknesses on the MSS distributionand evolving characteristics of surrounding rocks in unsymmetrical disposal andfully mechanized top-coal caving (FMTC),based on unsymmetrical disposal characteristics,the analyses of numerical simulation,material simulation and in-situ observation weresynthetically applied according to the geological and technical conditions of the 1151(3)working face in Xieqiao Mine.The results show that the stress peak value of the MSS-baseand the ratio of MSS-body height to caving thickness are nonlinear and inverselyproportional to the caving thickness.The MSS-base width,the MSS-body height,theMSS-base distance to working face wall and the rise distance of MSS-base beside coalpillar are nonlinear and directly proportional to the caving thickness.The characteristics ofMSS distribution and its evolving rules of surrounding rocks and the integrated cavingthickness effects are obtained.The investigations will provide lots of theoretic referencesto the surrounding rocks' stability control of the working face and roadway,roadway layout,gas extraction and exploitation,and efficiency of caving,etc.展开更多
Understanding roof behaviour and immediate roof failure patterns of longwall face is a prerequisite for establishing correct roof control theory and appplying effective roof control measures. Roof behaviour and immedi...Understanding roof behaviour and immediate roof failure patterns of longwall face is a prerequisite for establishing correct roof control theory and appplying effective roof control measures. Roof behaviour and immediate roof failure pattern have a close relationship with upper mining boundary conditions of longwall face. According to actual situation of Datong Mining Area,upper mining boundary conditions of longwall face have been classified into 5 types in this paper.Roof behaviour and immediate roof failure pattern under each upper mining boundary condition are discussed in details.展开更多
A mechanical model to control the top-coal deformation is established in accordance with the structural characters of the gob-side entry surrounding rock for the fully-mechanic top-coal caving; the analytical solution...A mechanical model to control the top-coal deformation is established in accordance with the structural characters of the gob-side entry surrounding rock for the fully-mechanic top-coal caving; the analytical solution of top coal roof-sag curve is deduced with Winkler elastic foundation beam model. By means of a calculating and analytic program, the top coal roof-sag values are calculated under the conditions of different supporting intensities, widths of narrow pillars and stiffness of top coal; meanwhile, the relationship between the roof-sag values and supporting intensity, width of narrow pillars and stiffness of top coal is analyzed as well. With the actual situation of the gob-side entry taken into consideration, the parameters of top-coal control are determined and a supporting plan is proposed for the top-coal control,which is proved to be reliable and effective by on-site verification. Some theoretical guidance and advice are put forward for the top-coal deformation control in gob-side entry for fully mechanized top-coal caving face.展开更多
基金Supported by the Plan of Young Backbone Teacher of Henan Provincethe Science and Technology Plan of China Coal Industry (MTKJ07-220)+2 种基金the Plan of Education Department of Henan Province (2007440004)the Plan of Science and Technology Department of Henan Province (072102240029)the Doctor Foundation of Hanan Polytechnic University (648190)
文摘Through theoretical analysis, simulation test and practice, the law of a fracture'sinfluence on hard top coal press cracking was studied. The study focused on the relationbetween fracture and coal strength, top coal caving ability and work face layout. Based onthe investigation of the fracture system, the control of press cracking was achieved bymatching working face to fracture orientation to improve top-coal caving ability and recovery. The matching principle was pointed out: The top-coal caving working face should beperpendicular to or obliquely cross the primary fracture at a large angle, and cross thesecondary fracture at a small angle. The rational match can increase the recovery ratio oftop-coal and avoid rib spalling. The application of control technology on hard top coalpress cracking was introduced at the Iongwall top-coal caving face.
基金Supported by National Basic Research Program(973)(2005cb221503)National Natural Science Foundation of China(50674003)Science and Technological Fund of Anhui Province for Outstanding Youth(08040106839)
文摘In order to explore the influence of different caving thicknesses on the MSS distributionand evolving characteristics of surrounding rocks in unsymmetrical disposal andfully mechanized top-coal caving (FMTC),based on unsymmetrical disposal characteristics,the analyses of numerical simulation,material simulation and in-situ observation weresynthetically applied according to the geological and technical conditions of the 1151(3)working face in Xieqiao Mine.The results show that the stress peak value of the MSS-baseand the ratio of MSS-body height to caving thickness are nonlinear and inverselyproportional to the caving thickness.The MSS-base width,the MSS-body height,theMSS-base distance to working face wall and the rise distance of MSS-base beside coalpillar are nonlinear and directly proportional to the caving thickness.The characteristics ofMSS distribution and its evolving rules of surrounding rocks and the integrated cavingthickness effects are obtained.The investigations will provide lots of theoretic referencesto the surrounding rocks' stability control of the working face and roadway,roadway layout,gas extraction and exploitation,and efficiency of caving,etc.
文摘Understanding roof behaviour and immediate roof failure patterns of longwall face is a prerequisite for establishing correct roof control theory and appplying effective roof control measures. Roof behaviour and immediate roof failure pattern have a close relationship with upper mining boundary conditions of longwall face. According to actual situation of Datong Mining Area,upper mining boundary conditions of longwall face have been classified into 5 types in this paper.Roof behaviour and immediate roof failure pattern under each upper mining boundary condition are discussed in details.
基金funded by the National Natural Science Foundation of China(No.51374201,51323004)the State Key Development Program for Basic Research of China(No.2013CB227900)the College Student’s Program for Innovation of China University of Mining and Technology of China(No.201507)
文摘A mechanical model to control the top-coal deformation is established in accordance with the structural characters of the gob-side entry surrounding rock for the fully-mechanic top-coal caving; the analytical solution of top coal roof-sag curve is deduced with Winkler elastic foundation beam model. By means of a calculating and analytic program, the top coal roof-sag values are calculated under the conditions of different supporting intensities, widths of narrow pillars and stiffness of top coal; meanwhile, the relationship between the roof-sag values and supporting intensity, width of narrow pillars and stiffness of top coal is analyzed as well. With the actual situation of the gob-side entry taken into consideration, the parameters of top-coal control are determined and a supporting plan is proposed for the top-coal control,which is proved to be reliable and effective by on-site verification. Some theoretical guidance and advice are put forward for the top-coal deformation control in gob-side entry for fully mechanized top-coal caving face.
