Migration law of gob-side roadway roof by gangue grouting filling in bottom collapse zone: analysis of influencing factor of gangue slurry filling degree
摘要
The stability of the gob-side roadway roof poses a significant challenge for safe mine production. To address this pressing issue, the gangue slurry utilization has emerged as a popular strategy to ameliorate the stress environment within gob-side roadways and bolster their structural integrity. Given the intricate nature of the internal structure of the collapse zone, this article investigates the various manifestations of key block structures within this zone, drawing insights from analogous simulation experiments. Mechanical models are established for both the key blocks and the gob-side roadway roof, meticulously analyzing the impact of the degree of slurry filling on the stability of these key blocks. Furthermore, the movement of the gob-side roadway roof is calculated, considering the shear forces exerted by the key blocks. The findings reveal that the gangue aggregate and fractured rock mass within the collapse zone collaborate to support the key blocks, effectively reducing the tangential force exerted by these blocks by more than 50%. As the filling degree of the gangue slurry gradually diminishes, the peak deflection of the basic roof gradually increases, with an average amplitude of 16.1%. These insights have been successfully applied in mine operations, demonstrating the feasibility of the gangue grouting filling method in the bottom collapse zone for controlling the surrounding rock of gob-side roadways. Specifically, when the elastic foundation coefficient of the slurry exceeds 0.11 × 106 N/m and the width of the coal pillar exceeds 5 m, the gob-side roadway remains stable and secure.
HighlightsGangue grouting stabilizes gob-side roadways by controlling filling degree. 87% filling cuts roof stress 50% via key block stabilization. Slurry+pillar maintains 3D stress, prevents lateral peak overlap.