纵横波扰动作用下巷道围岩动态损伤特征研究

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

  • 摘要: 煤岩破裂产生的震动波由纵波和横波组成,二者在振动方向和应力作用形式上存在差异,其对巷道围岩动力响应及损伤演化的差异性作用仍需进一步明确。以国网能源新疆准东煤电有限公司准东二矿1101工作面为工程背景,结合现场微震监测与数值模拟,基于微震波形拆分与重构实现纵横波分离和加载,研究纵横波作用下巷道围岩动态损伤特征,并分析微震能级、震源距和垂直应力对围岩动态损伤特征的影响规律。结果表明:① 现场微震事件主要集中于煤层顶底板、巷道邻近区域及采动影响侧,以中高能级事件为主,受巨厚煤层大采高、强采动影响,高静载应力与微震动载扰动叠加,导致巷道围岩损伤增强。② 纵波阶段,巷道围岩以顶板局部变形破坏为主,顶板、帮部和底板位移分别为0.03,0.02,0.01 m,塑性区主要在顶板及帮部局部区域扩展;横波作用后,顶板垂向变形和帮部水平变形增强,顶板和帮部累计位移分别增至0.12和0.08 m,塑性区由局部扩展向顶底板及两帮协同大范围扩展转换。③ 不同影响因素下,横波位移响应比为2.75~5.00,应力扰动比为1.47~2.48,横波诱发的塑性区占比为79.90%~94.90%,横波对巷道围岩变形累计和塑性损伤扩展的作用整体强于纵波;微震能级升高、震源距减小和垂直应力增大均会促进围岩动力响应和塑性损伤扩展。

     

    Abstract: 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.

     

/

返回文章
返回