Coal Pillar Size Determination and Surrounding Rock Control for Gob-Side Entry Driving in Deep Soft Coal Seams

In response to the large-scale instability failure problem of designing coal pillars and support systems for gob-side entry driving (GSED) in high-stress soft seams deep mines, main difficulties surrounding rock control GSED were analyzed. The relationship between position roof breaking line, together with width limit equilibrium zone a reasonable size pillar, quantified through theoretical calculations. calculations showed that maximum minimum widths pillar are 8.40 m 5.47 m, respectively. A numerical simulation was used study distribution characteristics evolution laws deviatoric stress plastic fields under different sizes. Theoretical analysis, simulation, engineering practice comprehensively applied determine narrow seams, which 6.5 m. Based on size, zones roadway, at positions advanced panel during mining, simulated, range roadway strengthening supports determined as 25 plasticization degree roof, entity boundary line peak after stability excavation obtained. Drilling crack detection conducted rib, development key areas clarified. Joint technology is proposed, includes combination channel steel anchor beam mesh, rib asymmetric truss cable grouting modification local fractured an single hydraulic support. selected high-strength combined reinforcement can effectively large deformations rock.