Dynamic damage characteristics of roadway surrounding rock under coupled longitudinal and transverse waves disturbances

Vibration waves generated by coal and rock fracture consist of longitudinal and transverse waves, which differ in vibration direction and mode of stress action. However, their different effects on the dynamic response and damage evolution of roadway surrounding rock have not yet been fully clarified. Taking the working face 1101 of Zhundong No.2 Mine, State Grid Energy Xinjiang Zhundong Coal Power Co., Ltd. as the engineering background, this study combined field microseismic monitoring with numerical simulation. Longitudinal and transverse waves were separated and independently applied through microseismic waveform decomposition and reconstruction to investigate the dynamic damage characteristics of roadway surrounding rock under longitudinal and transverse wave disturbances. The effects of microseismic energy level, source distance, and vertical stress on the dynamic damage characteristics of the surrounding rock were also analyzed. The results showed that: ① field microseismic events were mainly concentrated in the roof and floor of the coal seam, areas adjacent to the roadway, and the mining-affected side, with medium- and high-energy events predominating. Under the combined effects of the large mining height of the extra-thick coal seam, intensive mining disturbance, high static stress, and microseismic dynamic loading, damage to the roadway surrounding rock was aggravated. ② During the longitudinal-wave stage, the roadway surrounding rock was characterized mainly by local deformation and failure of the roof. The displacements of the roof, ribs, and floor were 0.03, 0.02, and 0.01 m, respectively, and the plastic zone expanded mainly in local regions of the roof and ribs. After the transverse-wave disturbance, the vertical deformation of the roof and the horizontal deformation of the ribs increased. The cumulative displacements of the roof and ribs increased to 0.12 m and 0.08 m, respectively, while the plastic zone expanded from local regions to large-scale coordinated development in the roof, floor, and both ribs. ③ Under different influencing factors, the transverse-wave displacement response ratio ranged from 2.75 to 5.00, the stress disturbance ratio ranged from 1.47 to 2.48, and the proportion of the plastic zone induced by the transverse wave ranged from 79.90% to 94.90%. Overall, the transverse wave exerted a stronger effect than the longitudinal wave on cumulative deformation and plastic damage propagation of the roadway surrounding rock. In addition, an increase in microseismic energy level, a decrease in source distance, and an increase in vertical stress all promoted the dynamic response and plastic damage propagation of the surrounding rock.