关键词: 正断层, 硬厚覆岩, 采动应力分布, 演化特征

Abstract: Mining stress appears singularity under the influence of faults of hard thick overburden. By using three-dimensional numerical simulation method, the evolutionary characteristics of mining stress with the working face advancing to normal faults and layout along normal faults have been studied．Research shows that normal faults significantly weaken the mining stress transmission of hard thick overburden and hence, the prominent obstruction of mining stress. Roof fault zone is in a low stress state, while the stress is concentrated in the bottom fault zone. When hanging wall is advancing to normal faults, the overburden between working face and faults becomes“inverted wedge”shaped，and the mining stress is high，which becomes the key areas of disaster prevention. The lateral overburden of faults is“wedge”shaped, and mining stress is lower than that of the stress of the primary rock. When footwall is advancing to normal faults, the mining stress is low. Under the influence of fault cut, strong bearing area is formed on the lateral coal body of the end of working face. High stress concentration area appears in the front of faults coal pillar or working face when the hanging working face is distributed along the fault strike, and the stress concentration of surrounding rock in roadway is prominent, which makes it become a key harnessing zone.

Key words: normal faults, hard-thick overburden, distribution of mining stress, evolutionary characteristics