Numerical Analysis of Synergistic Ground Control Efficacy via Integrated Mining-Backfill-Roof Contact in Metallic Deposits

To investigate the impact of Integrated Mining-Backfill-Roof Contact (IMBR) synergy on strata subsidence in metallic deposits and analyze strata/surface movement patterns, this study enables safe, efficient, environmentally conscious, and sustainable mining development. Focusing on a representative metal mine, we integrated laboratory testing, theoretical analysis, and numerical modeling to determine experimental parameters. Utilizing MIDAS GTS NX, numerical models incorporated four orebody dip angles (30°, 50°, 70°, 90°), five stress release coefficients (20–100%), and contacted/uncontacted conditions to assess IMBR’s control efficacy on surrounding rock stability and surface subsidence. By examining strata/surface movement under variable dip angles and stress release coefficients, displacement control mechanisms were quantified, revealing strata movement evolution principles. Key findings indicate: (1) For all dip angles, the increase rate of displacement progressively intensifies as the excavation stress release coefficient decreases. Notably, at a 30° dipping angle, the most pronounced reduction occurs under declining stress release coefficients, with overall displacement reduction rates reaching 17% for ground surface and 18% for surrounding rock, respectively. (2) Surface displacement impacts intensify as dip angles flatten. (3) Shallower dips induce more pronounced stress disturbance, expanding overburden movement domains and exacerbating surface impacts. Finite element numerical modeling enables accurate and effective analysis of strata and ground movement patterns under varying orebody dipping angles and mining-backfill stress release coefficients. Findings demonstrate that IMBR technology, compared to conventional roof-contacted backfilling methods, achieves timely roof support through immediate backfill-roof contact, significantly reduces overburden fracture propagation depth, and offers valuable insights for controlling surface subsidence in complex mining conditions—particularly for mining under surface structures.