关键词: 浅埋煤层, 高强度开采, 覆岩切落, 塌陷灾害, 灾害防控

Abstract: High intensity mining (HM) under shallow seam in a northwest China mining area is likely to develop into a overburden cutting subsidence disaster (OCSD), which poses a severe threat to the production safety and the ecological environment. To investigate the HM OCSD evolution mechanism and preventive technology, the panel 22407 in Halagou Coal Mine is used as an example, analogy simulation is employed to conduct analysis of the evolution pattern of a HM OCSD. The results show that a HM OCSD starts after immediate roof cantilever beam experiences cutting, and the overburden develops vertical cracks. As the panel advances further, the voussoir beam structure in the fractured zone becomes unstable, and the key stratum and bearing layer experience cutting, which leads to a subsidence disaster. Based on this study, a system mechanics model composed by the timber – gangue - cantilever beam - voussoir beam was established. The influence mechanism of disasters were analyzed from the overburden structure, lithology, loads and timber stiffness, weighting interval. A detailed preventive mechanism is proposed, which provides scientific support for HM production safety and ecological environmental protection.