Study on Stability of Roof- Coal Pillar in Room and Pillar Mining Goaf in Shallow Depth Seam

In order to reduce roof disaster dangers caused by the coal pillar stability lost in the room and pillar mining goaf, a numerical model of large area roof fal ling caused by the coal pillar stability lost in the room and pillar mining goaf was established and was applied to the analysis on the loading features of the coal pillars i n the room and pillar mining goaf. A dimension relationship of the coal pillar in the room and pillar mining goaf affected to the stability of the completed mining goaf was obtained. Based on the relationship between the pillar stress and strength in the room and pillar mining goaf, a numerical analysis model of the roof-coal pillar group sy stem was established in the room and pillar mining goaf in a shallow depth seam. A numerical simulation method was applied to the iterative calculation on the stability of the roof-coal pillar group system in the room and pillar mining goaf in Kuiwu Mine of Ordos Area. A prediction could be conducted on the stability and failure develop ment process of the room and pillar mining goaf in the mine, and a theoretical support could be provided to the evaluation on the stability of the roof-coal pillar group sy stem in the room and pillar mining goaf in a shallow depth seam.Meanwhile under the rheology condition, a coal pillar group stability lost process to cause large area ro of disaster could be reappeared.