Numerical Investigation of the Influence of Roof-Cutting Parameters on the Stability of Top Coal Gob-Side Entry Retaining by Roof Pre-Fracturing in Ultra-Thick Coal Seam

Gob-side entry retaining by roof cutting, a pillarless mining technique, plays critical role in maintaining continuous production, rapid connection, and enhancing the coal recovery rate fully mechanized top caving working faces. This technique stands as sustainable development method mining. The present research, set against backdrop of Yitang Coal Mine 100602 gob-side investigates influence roof-cutting borehole depth, dip angle, height, seam thickness on stability an ultra-thick under 12 distinct conditions. A typical model overburden structure post-roof pre-splitting was established to study failure mechanism roof. results reveal that angle depth pre-fracturing significantly impact movement characteristics overlying strata. Optimal conditions are found when borehole, 10°, 16 m, 4 respectively. Under these circumstances, load transfer from goaf can be effectively intercepted, mitigating fracture activities entry. Field measurements confirm suitable anchor-net support stabilize roof’s rock structure. research underpins significance for promotion application cutting seams.