Using the spatial structure of the external staggered split-level panel layout,a combined support technology for adjacent roadways was developed and analyzed for a rock bolt and anchor cable mechanism.The influence of...Using the spatial structure of the external staggered split-level panel layout,a combined support technology for adjacent roadways was developed and analyzed for a rock bolt and anchor cable mechanism.The influence of the side rock bolt and anchor cable parameters on the mechanical properties of the anchorage body and the support stress distribution of the lateral coal body were revealed using the FLAC3D software.The optimal support parameters of the side rock bolts and anchor cables were subsequently determined,and the support effect of gob-side entry in a mining scenario was verified.The results show that the support of the side rock bolts and anchor cables improves the mechanical properties and stress state of the anchorage body,producing a good protective effect on the coal body of the air-intake entry roof and side wall.This is beneficial to the stability of the side wall and the realization of the suspension effect for roof rock bolts and anchor cables,which in turn makes the surrounding rock maintenance of the gob-side entry to a thick coal seam more favorable.展开更多
Ground subsidence caused by extraction of longwall panels has always been a great concern all over the world.Conventional longwall mining system(CLMS)gives rise to wavy subsidence causing great damage to surface struc...Ground subsidence caused by extraction of longwall panels has always been a great concern all over the world.Conventional longwall mining system(CLMS)gives rise to wavy subsidence causing great damage to surface structures.A coal mine in Shanxi,China,utilizes a split-level longwall layout(SLL)for a sub-horizontal No.8 coal seam to improve the cavability of mudstone interlayer and top coal.This layout,however,also produced unexpectedly favorable surface subsidence.Subsidence of No.6 and No.8 longwall panels was monitored while mining was conducted.Field instrumentation and numerical simulation were carried out.It is demonstrated that an asymmetric subsidence profile with stepped subsidence and cracks occurred on the tailgate side but relatively mild and smooth deformation on the other.Due to elimination of conventional parallelepiped gate pillar,No.6 and No.8 gobs were connected.Extraction of two SLL panels acted as one supercritical panel.The maximum possible subsidence was reached which lowers the likelihood of potential future secondary subsidence as underground gob fractures and voids have closed.Therefore,SLL is more favorable for postmining land reuse as gobs are more consolidated underground.展开更多
基金National Natural Science Foundation of Surface Project of China(Grant Nos.5177428952074291)+2 种基金The National Natural Science Foundation of the Youth Science Foundation of China(Grant No.51404270)The Fundamental Research Funds for the Central Universities(Grant No.2011QZ06)The Open Fund of State Key Laboratory of Coal Resources in Western China(Grant No.SKLCRKF1903).
文摘Using the spatial structure of the external staggered split-level panel layout,a combined support technology for adjacent roadways was developed and analyzed for a rock bolt and anchor cable mechanism.The influence of the side rock bolt and anchor cable parameters on the mechanical properties of the anchorage body and the support stress distribution of the lateral coal body were revealed using the FLAC3D software.The optimal support parameters of the side rock bolts and anchor cables were subsequently determined,and the support effect of gob-side entry in a mining scenario was verified.The results show that the support of the side rock bolts and anchor cables improves the mechanical properties and stress state of the anchorage body,producing a good protective effect on the coal body of the air-intake entry roof and side wall.This is beneficial to the stability of the side wall and the realization of the suspension effect for roof rock bolts and anchor cables,which in turn makes the surrounding rock maintenance of the gob-side entry to a thick coal seam more favorable.
基金This study was funded by the General Program of the National Natural Science Foundation of China(52274092)Hu-Bao-E National Independent Innovation Demonstration Zone Construction Science and Technology Support Project(2023XM08)Funds for Talents Supported by the China Association for Science and Technol-0gy(YESS20200211).
文摘Ground subsidence caused by extraction of longwall panels has always been a great concern all over the world.Conventional longwall mining system(CLMS)gives rise to wavy subsidence causing great damage to surface structures.A coal mine in Shanxi,China,utilizes a split-level longwall layout(SLL)for a sub-horizontal No.8 coal seam to improve the cavability of mudstone interlayer and top coal.This layout,however,also produced unexpectedly favorable surface subsidence.Subsidence of No.6 and No.8 longwall panels was monitored while mining was conducted.Field instrumentation and numerical simulation were carried out.It is demonstrated that an asymmetric subsidence profile with stepped subsidence and cracks occurred on the tailgate side but relatively mild and smooth deformation on the other.Due to elimination of conventional parallelepiped gate pillar,No.6 and No.8 gobs were connected.Extraction of two SLL panels acted as one supercritical panel.The maximum possible subsidence was reached which lowers the likelihood of potential future secondary subsidence as underground gob fractures and voids have closed.Therefore,SLL is more favorable for postmining land reuse as gobs are more consolidated underground.
