Research on the Evolution Law of Overlying Strata Movement in Fully Mechanized Coal Mining Face Based on Similarity Simulation

Abstract

Based on the similarity material simulation experiment method, a systematic study was conducted on the movement law of overlying strata in the B8 coal seam fully mechanized mining face of Xiaogou Branch Mine, Nanshan Coal Mine. By constructing a similarity material model, the collapse, separation, and displacement changes of the overlying strata during the coal seam mining process were simulated. The roof pressure behavior, bedrock movement law, and development characteristics of the "three zones" were analyzed. The experimental results indicate that the initial roof pressure step distance of the working face is approximately 50m, with periodic pressure step distances ranging from 15m to 30m. The height of the roof caving zone is 8.25 times the mining height, the height of the fractured zone is 22 times the mining height, and there exists a 40m bent subsidence zone at the uppermost part of the bedrock. The research findings provide a scientific basis for mine safety production and support design.