Surrounding rock deformation characteristics and control strategies during passing through abandoned roadway group

The disorderly mining activities and irrational layout in underground coal mines have left a large number of adjacent abandoned roadways. During the process of a working face passing through abandoned roadways, these structures are prone to varying degrees of damage, with frequent occurrences of roof leakage and induced rock burst accidents, significantly impacting subsequent mining operations and safe production. To address these issues, this study investigates the surrounding rock deformation patterns during fully mechanized mining face passage through abandoned roadway clusters. Specific countermeasures were systematically summarized according to different occurrence characteristics of abandoned roadways. Through mechanical analysis, the critical unstable width of coal pillars was determined to be approximately 16.1~16.8 m. A three-dimensional numerical model was established based on 17 abandoned roadways with various shapes and occurrences in the working face. Simulation results indicate severe deformation and failure in roof rock layer roadways, while floor roadways exhibit relatively minor damage. Notably, when the distance between abandoned roadways and the coal seam exceeds 8 m, almost no damage occurs. Three technical measures for passing through abandoned roadway group was proposed according to their occurrence characteristics and implemented in engineering practice. Field applications demonstrate limited coal stress variations and weak strata pressure manifestations during the crossing process, ensuring safe passage through abandoned roadway clusters. This achievement enables efficient and safe crossing of abandoned roadway group in fully mechanized mining faces, enhances coal recovery rates, and provides practical engineering references for similar geological conditions.