Influencing Factors and Adaptability of Working Face Length in Deep Thick Coal Seam

In order to study the influencing factors of the working face length in deep buried thick coal seam, the 1,106,110 working face of Meihuajing Coal Mine was taken as the object, and the influencing factor model was established by using AHP. The analysis shows that the main controlling factors of working face length are coal mining technology, coal thickness and surrounding rock properties, accounting for 32.2%, 14.9% and 11.3% respectively. Based on the main controlling factors, the adaptability of the length and mining height of the working face and the support layout parameters of different roadway sections are studied. The results show that: when the mining height is 4 m, the peak value of the leading bearing pressure at the square of the working face is 54.03 MPa; when the mining height increases to 4.5 m and 5 m respectively, the stress peak value increases by 17.6% and 26.15%; When increasing to 5 m, the peak stress increases only by 7.28%. Combined with the high load margin of the hydraulic support, the mining height should be adjusted to 5 m. When the bolt support spacing is 800 mm, the synergistic effect between the top bolts is good, but the side bolts have a large anchoring blind area, and an anchor cable of the same specification should be added to each of the two sides. The research results can provide a reference for the reasonable length selection of the deep coal seam working face in the mining area.