Abstract:
Compared with near-horizontal and gently inclined coal seams, the characteristics of overburden strata collapse and migration during mining in inclined coal seams are significantly different. To address the challenges of mine water hazard prevention and control under multi-source recharge conditions, this paper takes the
2418 extraction face of Hexi Mine as the engineering background. Focusing on the longwall top-coal caving mining technology in inclined coal seams, a comprehensive approach combining similar material simulation experiments, numerical simulation calculations, and in-situ monitoring is adopted to systematically explore the coupled evolution mechanism of the "fracture field-stress field-seepage field" within the mining-induced overburden strata. The research results show that as the extraction face advances, the height of overburden fractures initially increases gradually to a peak and then stabilizes. The fracture development in the inclined direction exhibits a non-uniform characteristic of "upper part > middle part > lower part"; on the dip section, the vertical stress distribution of the roof and floor is asymmetric, with the stress release zone of the roof biased towards the upper-middle part and the stress release zone of the floor concentrated in the lower-middle part. The mining-induced fractures penetrate to form water-conducting channels, driving the water in the aquifer to seep into the mined-out area, resulting in the pore pressure of the roof and floor decreasing to negative values, and this low-pressure seepage zone continues to expand deeper with the extraction progress. Based on the above laws, a graded water hazard prevention and controltechnology system suitable for different water sources is proposed, providing theoretical basis and engineering reference for safe and efficient mining in inclined coal seams under similar geological conditions.