煤铝协调开采采掘叠加扰动巷道锚注梯级协同支护承载特性OA

In coal-bauxite coordinated mining areas,the development and extension roadways are subjectd to long-term superimposed disturbances from multiple stress sources associated with roadway excavation,coal extraction,and bauxite mining.Conventional bolt-shotcrete systems are often insufficient to maintain surrounding-rock stability under such compounded disturbance conditions.To ensure long-term stability,an integrated methodology framework combining laboratory rock-mechanics testing,similar-material model test,and in situ stress inversion was implemented.The physico-mechanical properties and in situ stress distribution at the Chejiazhuang Coal Mine were systematically characterized,and the failure-evolution process of the roadway under superimposed excavation-mining disturbances was examined.On this basis,a tiered bolt-grouting collaborative support system was proposed,and its load-bearing behavior was investigated.The results indicate that the proposed system effectively reduces roof stress concentration and establishes a stable load-transfer path along the ribs.Under unsupported conditions,the ultimate bearing capacity of the surrounding rock is 4.93 MPa;with the tiered collaborative support system,it increases to 7.10 MPa.These findings demonstrate a substantive improvement in the load-bearing capacity of roadways subjected to excavation-mining superimposed disturbances and an effective restraint of large-deformation and instability of the surrounding rock.