LAUSR

In order to determine whether the upper coal seams No. 5 and No. 6 can be mined after the coal seam No. 8 of Hulonggou coal mine adopted irregular roadway mining, in this study, the key factors affecting the upward mining of Hulonggou coal mine are studied by using the similar material experiment and numerical simulation experiment, and the feasibility of the upward mining is analyzed. Results demonstrate that the collapse area of roof is small and the height of roof crack zone is 2–4.5 m due to irregular roadway mining in the coal seam No. 8, the hard and thick strata are not easy to break in the process of mining, which hinders the expansion of fissures to the upper strata and avoids dislocation in the upper strata. There are no broken fractures and rock stratum dislocation in the coal seam and its roof and floor strata before No. 5 and No. 6 coal mining. The experiments of similar material and numerical simulation show that it is feasible for upward mining above the goaf of irregular roadway mining in Hulonggou coal mine.