Influence of rock body transportation in inclined coal seam mining airspace on the stability of surrounding rock along the empty roadway

Aiming at the influence of rock transport characteristics in the tilted coal seam on the stability of the peripheral rock along the open roadway, we took Zhuangzihe Coal Mine as the research object, and revealed the distribution law of the peripheral rock stress field, the evolution mechanism of the plastic damage, and the mechanical response characteristics of the roadway support structure during the full service cycle of the open roadway through the numerical simulation technology of FLAC3D. The results show that the over-head bearing stress field and lateral residual stress field under inclined coal seam conditions show a gradient increasing law with the increase of burial depth; the influence of secondary mining significantly increases the peak value of over-head bearing stress (by 43%) and its influence range (by 28%), which triggers the increase of lateral stress concentration coefficient to 1.75; the collapsed rock body in the mining area forms an asymmetric support effect on the roof plate, which results in the downgrade and shear damage and penetrates the mine shaft; and the rock body collapses in the mining area to form an asymmetric support effect on the roof plate, which leads to the downgrade and shear damage and the penetration of the mine shaft. Shear damage and penetration through the plastic zone of the roof plate in the mining hollow zone; although the existing roadside support structure meets the strength index (strength safety reserve coefficient K=4), its resistance to lateral deformation is insufficient.