Study on Overlying Strata Movement and Structure Features Aroused by Mountainous Shallow Buried Coal Seam Mining

When mountainous shallow- buried coal seam mined, the strata behaviors were intense and even some supports crushed or the tail beam and roof beam separated. Contraposing this phenomenon, it analyzed the overlying strata movement rule and structure features aroused by mountainous shallow-buried coal seam mining with Distinct Element Method. When mountainous shallow-buried coal seam mined, the overlying strata up to the surface would collapse, fall, and the horizontal displacement along mountain slope was apparent. The overlying strata would form relatively independent "two-zone" structure, the horizontal stress among the rocks was weak, and can not form bearing structure with necessary bearing property by itself. It made the load on supports increase and strata behaviors became intense. This article also pointed out the conditions to form this "two-zone" structure.