Gateway Retained Along Goaf Technology with Pier Pillar Backfilled with High Water Material in High Gassy Mine

In order to improve a high timber consumption, high labor intensity, complicated construction and low support strength of the timber pack gateway retain ed along the goaf, a high water material was applied to backfill the pier pillar for the gateway retained along the goaf technology in Gaohe Mine and the industrial trial W as conducted in No. E1302 air return gateway. The results showed that the max convergence between the roof and floor of the timber pack gateway retained along the goaf was 286 mm, the max convergence between the roof and floor of the gateway retained along the goaf with the pier pillar backfilled with the high water material was 188 mm and the max deformation value of the pier pillar was 65 mm. The construction technology of the gateway retained along the goaf with the pier pillar backilled wi th the high water material was simple. The compressive strength of the pier pillar was high and could control the deformation of the surrounding rock. Meanwhile, the ve ntilation cross section enlarged of the mine roadway would be favorable for the ventilation gas discharging and could prevent the gas accident occurred in the mine.