Study on Supporting Key Technology of Driving Roadway along Goaf on Down Original Site in Island Light Sublevel Caving Face

摘要

The concept of driving roadway along goaf on "down original site" was proposed based on analysis of the formation condition of island pillar in 2123 face of Shigejie mine. The reasonable width of narrow pillar for roadway protection was 2.0 m by calculation, and the position of driving roadway along goaf on "down original site" that the mining roadway in neighboring face was arranged down the original abandoned roadway of the last district and was determined through key block, internal and external stress field and limit equilibrium theory. Joint supporting form of ribs bolt, netting and shelf along goaf was designed through strength reinforced theory of roadway bolting supporting surrounding rock. Spacing and row distance of I-steel was 800×800 mm, glass steel bolting Φ18×2000 mm, rebar bolt Φ20×1500 mm, and spacing and row distance was 800x800 mm. Industrial field tests show that roadway layout and joint supporting method are feasible and effective in controling deformation of roadway surrounding rock, ensuring normal use of roadway during the mining period.