Field Study on the Evolution of Mining-induced Stress and Deformation of Coal Mining Roadway Surrounding Rock During the Full Heading-Mining Cycle

Measuring and monitoring the full-cycle mining-induced stress and deformation of roadway surrounding rock, and further investigating their distribution characteristics and evolution laws, are of great significance for coal mining engineering. Using hollow inclusion stress gauges and acoustic multi-point displacement meters, the full-cycle stress and deformation evolution data (from heading to the end of mining) were obtained through on-site measurements in the auxiliary transport roadway of the 122110 working face, Caojiatan Coal Mine. The results show that the range of mining-induced stress manifestation is 8 m and 110 m ahead of the working face during the heading and mining periods, respectively. The difference between the maximum and minimum principal stresses increased by 0.17 times during heading and 1.34 times during mining, which is 7.9 times higher than that during heading. Surrounding rock deformation gradually occurs from shallow to deep zones, with the deformation magnitude in shallow areas being larger than that in deep areas. The overall deformation during heading is relatively small, while it increases significantly during mining, but, accompanied by a lower deformation rate. During heading, the surrounding rock failure mode is dominated by tensile failure in the surface layer; during mining, large-scale plastic failure occurs, with shallow rock mainly undergoing tensile failure, mid-shallow rock undergoing tensile-shear composite failure, and deep rock remaining intact. Combined with measured data, borehole televiewing results, and in-situ failure characteristics, the stress ratio K is verified to effectively reflect the relationship between the stress state and failure mode of roadway surrounding rock.