The 110-mining method,a rising and revolutionary non-pillar longwall mining method,can obviously expand coal extraction ratio and minimize roadway incidents.However,in case of composite hard roof,problems such as diff...The 110-mining method,a rising and revolutionary non-pillar longwall mining method,can obviously expand coal extraction ratio and minimize roadway incidents.However,in case of composite hard roof,problems such as difficulty in commanding the entry steadiness and insufficient fragmentation and bulking of the goaf gangue are prevalent.In this study,a 110-mining method for roadway surrounding rock stability control technology based on a compensation mechanism was proposed.First,the composite hard roof cutting short cantilever beam(SCB)model was built and the compensation mechanism including stress and space dual compensation was studied.Subsequently,the controllable elements influencing the roadway steadiness were confirmed to consequently put forward a control technology based on stress compensation for entry support and space compensation for the fragmentation and bulking of goaf gangue.The control technology was finally verified through onsite engineering experiments in terms of composite hard roof.The adoption of the 110-mining method with compensation control technology indicated good support effect on the roadway.The initial and residual expansion coefficients of the goaf gangue increased by 0.6 and 0.6,respectively,and the maximum and average working resistances of the working face support decreased by 10.9%and 13.8%,respectively.Consequently,the deformations of reserved entry decreased,and entry steadiness was enhanced.The presented technique and effects got probably have practical values for non-pillar mining functions in comparable field.展开更多
This paper explores the deformation mechanism and control technology of roof pre-splitting for gob-side entries in hard roof full-mechanized longwall caving panel(LTCC).The investigation utilizes a comprehensive appro...This paper explores the deformation mechanism and control technology of roof pre-splitting for gob-side entries in hard roof full-mechanized longwall caving panel(LTCC).The investigation utilizes a comprehensive approach that integrates field monitoring,theoretical analysis,and numerical simulation.Theoretical analysis has illuminated the influence of the length of the lateral cantilever beam of the main roof(LCBM)above the roadway on the stability of the gob-side entry behind the panel.Numerical simulations have further revealed that the longer LCBM results in heightened vertical stress within the coal pillar,developed cracks around the roadway,and more pronounced damage to the roadway.Moreover,numerical simulations also demonstrate the potential of roof pre-splitting technology in optimizing the fracture position of the hard roof.This technology significantly reduces the length of the LCBM,thereby alleviating stress concentration in the coal pillars and integrated coal rib while minimizing the destruction of the gob-side entry.Therefore,this manuscript first proposes the use of roof pre-splitting technology to control roadway deformation,and automatically retain the entry within a hard roof LTCC panel.Field implementation has demonstrated that the proposed automatically retained entry by roof pre-splitting technology effectively reduces gob-side entry deformation and achieves automatically retained entry.展开更多
基金This work described herein was supported by the Program of China Scholarship Council(202206430008)the National Natural Science Foundation of China(NSFC)(52074300 and 52304111)+1 种基金the Yueqi Young Scholars Project of China University of Mining and Technology Beijing(2602021RC84)the Guizhou province science and technology planning project([2020]3007 and[2020]2Y019).
文摘The 110-mining method,a rising and revolutionary non-pillar longwall mining method,can obviously expand coal extraction ratio and minimize roadway incidents.However,in case of composite hard roof,problems such as difficulty in commanding the entry steadiness and insufficient fragmentation and bulking of the goaf gangue are prevalent.In this study,a 110-mining method for roadway surrounding rock stability control technology based on a compensation mechanism was proposed.First,the composite hard roof cutting short cantilever beam(SCB)model was built and the compensation mechanism including stress and space dual compensation was studied.Subsequently,the controllable elements influencing the roadway steadiness were confirmed to consequently put forward a control technology based on stress compensation for entry support and space compensation for the fragmentation and bulking of goaf gangue.The control technology was finally verified through onsite engineering experiments in terms of composite hard roof.The adoption of the 110-mining method with compensation control technology indicated good support effect on the roadway.The initial and residual expansion coefficients of the goaf gangue increased by 0.6 and 0.6,respectively,and the maximum and average working resistances of the working face support decreased by 10.9%and 13.8%,respectively.Consequently,the deformations of reserved entry decreased,and entry steadiness was enhanced.The presented technique and effects got probably have practical values for non-pillar mining functions in comparable field.
基金Project(52104139)supported by the National Natural Science Foundation of China Youth Science FoundationProject(SKLGDUEK2132)supported by the State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology/China University of Mining and Technology-BeijingProjects([2020]2Y030,[2020]2Y019,[2020j3007,[2020]3008,and[2022j0il]supported by the Guizhou Province Science and Technology Planning,China Project(2022B01051)supported by the Key Research and Development Special Tasks of Xinjiang,China。
文摘This paper explores the deformation mechanism and control technology of roof pre-splitting for gob-side entries in hard roof full-mechanized longwall caving panel(LTCC).The investigation utilizes a comprehensive approach that integrates field monitoring,theoretical analysis,and numerical simulation.Theoretical analysis has illuminated the influence of the length of the lateral cantilever beam of the main roof(LCBM)above the roadway on the stability of the gob-side entry behind the panel.Numerical simulations have further revealed that the longer LCBM results in heightened vertical stress within the coal pillar,developed cracks around the roadway,and more pronounced damage to the roadway.Moreover,numerical simulations also demonstrate the potential of roof pre-splitting technology in optimizing the fracture position of the hard roof.This technology significantly reduces the length of the LCBM,thereby alleviating stress concentration in the coal pillars and integrated coal rib while minimizing the destruction of the gob-side entry.Therefore,this manuscript first proposes the use of roof pre-splitting technology to control roadway deformation,and automatically retain the entry within a hard roof LTCC panel.Field implementation has demonstrated that the proposed automatically retained entry by roof pre-splitting technology effectively reduces gob-side entry deformation and achieves automatically retained entry.
基金Project(202206430008) supported by the China Scholarship Council ProgramProject (52104139) supported by the National Natural Science Foundation of China+2 种基金Project(SKLGDUEK2132) supported by the State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining&Technology/China University of Mining&Technology,Beijing,ChinaProjects([2020]2Y030,[2020]2Y019,[2020]3007,[2020]3008,[2022]011) supported by the Science and Technology Planning of Guizhou Province,ChinaProject(2022B01051) supported by the Key Research and Development Special Tasks of Xinjiang Uygur Autonomous Region,China。
