在综合考虑围压及刀具切削顺序的前提下，利用二维离散单元法建立双把TBM刀具切削节理不发育岩石的仿真模型，模拟出岩石裂纹的生产与扩展全过程。根据获得的裂纹扩展形态以及破碎块形成规则，总结归纳出四种典型破碎模式，并从刀具破岩效率、岩石裂纹扩展能力以及岩石破碎块度三个方面对刀具破岩机理进行进一步研究。仿真结果表明：随着围压的增加，刀具的破岩效率与裂纹扩展能力降低；同时加载方式下破岩效率比先后加载方式要大，而裂纹扩展能力则刚好相反；岩石破碎块度与破碎模式有关。%Considering the effects of confining pressure and cutting sequence, 2-D simulation models of rock-breaking by double TBM cutters were established by using the discrete element method. The process of induction and propagation of cracks was successfully simulated. According to the style of crack propagation and the formation of fragments, four typical types of breaking modes were identified. Further analyses were conducted to study the breaking efficiency, the abl}ity of crack expansion and the roc）~ fragment sizes. Besults indicated lba~ as ~be confining pressure increased, the breaking efficiency and the ability of crack expansion decreased. The breaking efficiency under simultaneous loading was more than that under sequential loading, while for the ability of crack expansion it was just the opposite. The rock fragment size was relevant to the breaking mode.
展开▼
