Strata Behavior Laws in Lower Slicing Mining of Contiguous Seams

Overlying strata movement laws of lower slicing in Luxi Coal Mine is studied by workface support force, deformation of the surrounding rock, borehole stress, anchor working resistance and hydraulic prop stress in crossheading. The results show that initial caving interval of the immediate roof in lower slicing is 15.6 m and the upper is 26.1 m. Initial caving interval of the main roof is 31.8 m and periodic weighting length is between 10~13 m. The average resistance of hydraulic-support-ZY4800/18/38 in workface is 27.2 MPa, which is 86.4% of the rated. The hydraulic-supports have better adaptability. Through the analysis of abutment pressure distribution characteristic in rail crossheading and belt crossheading, influence scope of advanced support pressure is 24.6 m in rail crossheading, and it is 31.135 m in belt crossheading.