ABSTRACT
Coal pillar roadway protection in zero section is generally realized by retaining roadway along gob or digging roadway along gob. Among them, gob-side retaining roadway needs to be affected by mining twice, which leads to high maintenance cost. However, small coal pillars still need to be set in gob-side excavation roadway, so the effect and cost of roadway protection are often not ideal. In this paper, the performance of the pre-filled activated coal gangue concrete wall in underground working face is studied by numerical simulation and physical experiment. The results show that: 1) The wall provides a certain support force and the stress on the left side of the wall is obviously transferred to the deep after the wall is preloaded with solid coal in the adjacent lower section. 2) The strength of concrete test blocks prepared with activated coal gangue powder (5% of slaked lime powder) replaced by cement meets the basic requirements of filling wall after 28-day of indoor curing at 19~21℃ and 95~99% humidity, which can be used as reference for practical application.
