The arching effect of surrounding rock pressure is critical for ground pressure control in mining areas. Taking a stope in Malipo tungsten mine as the engineering background, this study optimizes stope structural parameters based on the arching pressure theory. Analysis of the stope pressure arch shape equation shows that the pressure arch shape is mainly determined by the lateral pressure coefficient (λ) and stope span (L), while the actual load on pillars equals the weight of rock mass within the overlying pressure arch shell. Pillar loads differ at various stope locations. Combined with the pillar area bearing theory, the rock weight supported by pillars at different stope positions under the arching pressure theory was determined, and a load calculation formula for pillars at various locations was derived. A stope pillar size optimization method was also proposed, which overcomes the defect of excessively large pillar sizes caused by the pillar area bearing theory. It ensures pillar stability during mining while improving ore recovery rates. Taking an existing 830 m-deep stope in the tungsten mine as an example, the optimization method based on the arching pressure theory determined the actual required widths of pillars at different locations. This increased the ore recovery rate from the original 67.56% to 69.47% (an increase of 1.91%). This study provides a reference for the reasonable setting of pillar sizes.

To clarify the influence of pulverized coal gradation on the cyclic damage behavior of grouted consolidated bodies, this study used cement-pulverized coal composites as the research object. Three pulverized coal contents (10%, 20%, and 30%) and three pulverized coal particle radii (300 μm, 75 μm, and 28 μm) were designed, and cyclic loading-unloading tests, damping-energy separation analysis, and PFC numerical simulations were performed. Based on an equivalent single-degree-of-freedom model, a damping-energy calculation method was established, and a modified damage factor considering the damping effect was proposed to distinguish damping energy consumption from damage energy consumption within the hysteretic dissipated energy. The results show that, when the pulverized coal particle radius decreases from 300 μm to 28 μm, the specimen density increases by 9.94%–12.24%, whereas slurry fluidity decreases by 28.26%–82.93%. This indicates that fine pulverized coal can improve the compactness of the consolidated body but reduces slurry workability. The uniaxial compressive strengths of specimens with different gradations range from 10.17 to 46.04 MPa, suggesting that 28 μm pulverized coal is beneficial for enhancing the load-bearing capacity of the specimen, whereas a pulverized coal content of 30% weakens the continuous cemented structure of the cement matrix. During cyclic loading, the total mechanical energy density, elastic energy density, and damping energy density all increase nonlinearly with the number of cycles. The modified damage factor is lower than the conventional energy-based damage factor, indicating that ignoring the damping effect overestimates the actual damage degree of the material. PFC moment-tensor analysis shows that specimen failure is dominated by tensile cracks, with tensile cracks accounting for 28.00%–39.00%, whereas shear cracks and compression-closure cracks account for 21.00%–30.00% and 21.00%–28.00%, respectively. The results indicate that pulverized coal gradation controls the cyclic damage evolution of grouted consolidated bodies by altering particle packing, interfacial friction, damping dissipation, and crack propagation. These findings provide a quantitative basis for evaluating the vibration resistance of coal-pillar grouted reinforcement under cyclic mining-induced loading.