DOI: 10.11799/ce202502014
Development patterns of the"two zones"in overlying strata under multiple key layers during contiguous coal seams mining
TIAN Weidong
YANG Fan
MU Guohu
NIU Shengli
WANG Junqi
Abstract：Based on the engineering context of the 220608 and 220707 working faces at Zaoyuan Coal Mine,we employed a comprehensive methodology integrating theoretical analysis,borehole peeping,and numerical simulation to investigate the development patterns of the"two zones"(the caved zone and the water-conducting fracture zone)in overlying strata during contiguous coal seam mining under multiple key layers.The findings reveal that during the single-seam mining of the No.6 coal seam,the heights of the caved zone and the water-conducting fracture zone are 8.45 m and 28.64 m,respectively.However,when the No.6 and No.7 coal seams are mined in combination,these heights increase significantly to 23.19 m and 55.24 m,respectively.Quantitative analysis of borehole peeping observations,combined with the characteristics of the plastic zone in numerical simulations,provides a systematic understanding of the development patterns of the"two zones."The study highlights that the fracture of key layers plays a critical role in determining the rate and extent of the development of the"two zones."Additionally,the mining of coal seam groups induces repeated stress changes in the key layers,increasing the uncertainty of their failure.Under overlying aquifer conditions,this uncertainty makes strata collapse and mine water inrush events more unpredictable.
Keywords：contiguous coal seamsoverlying strata failurekey layer controlborehole peepingnumerical simulation
Publication Date：2025-02-28
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：9( 94-102 )