关键词: 错层位, 沿空掘巷, 双屈服, 采空区, 冲击倾向, 高应力

Abstract: The gateroads on the sides of a longwall panel at Zhenchengdi Coal Mine are driven along the roof and floor, respectively, and thus the gateroad along the floor becomes the gob-side entry under a longwall gob. In this paper, theoretical analysis, physical modelling, numerical modelling and field observation are conducted to investigate structures and stress of surrounding rock mass of this gob-side gateroad. It is found that the gob-side entry is independent of the side and front abutment pressures. The caved rock cushion under the masonry beam structure can dissipate energy and stress for the gob-side entry, which prevents from dynamic and impact loads, providing the stable stress environment much lower than pre-mining stress. The angle of break developed due to strata movement has a significant effect on stress and distribution (especially on gob edge). The lower the angle of break is, the smaller the gob pressure and stress are around the entry, and the larger distance between the gob edge to the location where pre-mining pressure occurs. The angle of break has a dictating and guiding function for the plastic zone development. The stress of surrounding rock mass of gob-side entry is significantly lower than premining stress with the high destress degree. Both the roof to floor and rib to rib convergences are smaller than that of non-gob-side entry, which demonstrates that overall stress environment is improved. The study is of certain drawing significance for highly stressed burst-prone gateroads.

Key words: split-level, gob-side gateroad driving, double yield, gob, burst-prone, high stress