Addressing the issues of significant entry settlement and severe mining pressure manifestations in the conventional 121 approach,an innovative N00 approach is proposed.By comparing the mining process and entry formati...Addressing the issues of significant entry settlement and severe mining pressure manifestations in the conventional 121 approach,an innovative N00 approach is proposed.By comparing the mining process and entry formation process of different approaches,the characteristics of entry roof settlement evolution under different approaches are obtained.The N00 approach,which incorporates roof cutting and NPR cable support,optimizes the mining and entry formation process to reduce the settlement phase of entry roof,decreases the settlement of entry roof,and enhances the steadiness of entry roof.The N00 approach modifies the entry roof structure through roof cutting and establishes a hydraulic support load mechanics model for the mining panel to derive the theoretical load pressure formula for the N00 approach’s hydraulic support.Compared with the conventional 121 approach,the pressure on the N00 approach’s hydraulic support is reduced.Empirical data obtained through field monitoring demonstrate that the N00 approach has reduced the roof settlement of the entry and weakened the mining pressure manifestation at the mining panel,achieving the goal of protecting the entry and mining panel.展开更多
Room and pillar sizes are key factors for safe mining and ore recovery in open-stope mining. To investigate the influence of room and pillar configurations on stope stability in highly fractured and weakened areas, an...Room and pillar sizes are key factors for safe mining and ore recovery in open-stope mining. To investigate the influence of room and pillar configurations on stope stability in highly fractured and weakened areas, an orthogonal design with two factors, three levels and nine runs was proposed, followed by three-dimensional numerical simulation using ANSYS and FLAC3~. Results show that surface settlement after excavation is concentrically ringed, and increases with the decrease of pillar width and distances to stope gobs. In the meantime, the ore-control fault at the ore-rock boundary and the fractured argillaceous dolomite with intercalated slate at the hanging wall deteriorate the roof settlement. Additionally, stope stability is challenged due to pillar rheological yield and stress concentration, and both are induced by redistribution of stress and plastic zones after mining. Following an objective function and a constraint function, room and pillar configuration with widths of 14 m and 16 m, respectively, is presented as the optimization for improving the ore recovery rate while maintaining a safe working environment.展开更多
基金Project(2022XDHZ12)supported by the Lvliang Technology Project,ChinaProjects(8232056,2232080)supported by the Beijing Natural Science Foundation,ChinaProject([2020]3008)supported by the Science and Technology Projects in Guizhou Province,China。
文摘Addressing the issues of significant entry settlement and severe mining pressure manifestations in the conventional 121 approach,an innovative N00 approach is proposed.By comparing the mining process and entry formation process of different approaches,the characteristics of entry roof settlement evolution under different approaches are obtained.The N00 approach,which incorporates roof cutting and NPR cable support,optimizes the mining and entry formation process to reduce the settlement phase of entry roof,decreases the settlement of entry roof,and enhances the steadiness of entry roof.The N00 approach modifies the entry roof structure through roof cutting and establishes a hydraulic support load mechanics model for the mining panel to derive the theoretical load pressure formula for the N00 approach’s hydraulic support.Compared with the conventional 121 approach,the pressure on the N00 approach’s hydraulic support is reduced.Empirical data obtained through field monitoring demonstrate that the N00 approach has reduced the roof settlement of the entry and weakened the mining pressure manifestation at the mining panel,achieving the goal of protecting the entry and mining panel.
基金Projects(50934002,51074013,51104100)supported by the National Natural Science Foundation of ChinaProject(IRT0950)supported by the Program for Changjiang Scholars and Innovative Research Team in University of China
文摘Room and pillar sizes are key factors for safe mining and ore recovery in open-stope mining. To investigate the influence of room and pillar configurations on stope stability in highly fractured and weakened areas, an orthogonal design with two factors, three levels and nine runs was proposed, followed by three-dimensional numerical simulation using ANSYS and FLAC3~. Results show that surface settlement after excavation is concentrically ringed, and increases with the decrease of pillar width and distances to stope gobs. In the meantime, the ore-control fault at the ore-rock boundary and the fractured argillaceous dolomite with intercalated slate at the hanging wall deteriorate the roof settlement. Additionally, stope stability is challenged due to pillar rheological yield and stress concentration, and both are induced by redistribution of stress and plastic zones after mining. Following an objective function and a constraint function, room and pillar configuration with widths of 14 m and 16 m, respectively, is presented as the optimization for improving the ore recovery rate while maintaining a safe working environment.
