复合岩层中TBM滚刀与围岩相互作用机理的数值模拟研究

Numerical study of interaction mechanism between TBM cutters and surrounding rock in composite rock strata

为提高硬岩隧道掘进机(tunnel boring machine,TBM)在复合岩层的掘进效率,采用PFC2D(particle flow code 2D)探讨了不同围压下复合岩层裂纹扩展机制,同时采用定量的方法揭示了滚刀间距、贯入度及岩层倾角对破岩效率的影响。结果表明:1)滚刀同软岩直接接触时,滚刀下部裂纹较多,而消耗的能量较少。相反,滚刀同硬岩直接接触时,滚刀下部裂纹较少,消耗的能量却较多。2)岩层倾角对破岩效率的影响较大,45°、90°为破岩效率较高的2个极值点。3)刀间距为70和120mm时比能较小,破岩效率高。4)滚刀破岩以张拉破坏为主,剪切破坏为辅。研究结果可以为复合岩层中TBM刀盘设计及TBM施工提供一定的理论依据。

In order to improve efficiency of tunnel boring machine （TBM） construction in composite rock strata, the interaction mechanism between surrounding rock mass and cutters was carried out. The crack propagation mechanism of composite rock stra-ta under different confining pressures was evaluated by using PFC2D. Meanwhile, the quantitative method was used to study the influence of cutter spacing, penetration and dip angle of rock stratum toward rock breaking efficiency. It can be concluded that cutters have more cracks when the cutters directly contacted the soft rock. However, energy consumption is low. On the contra-ry, cutters have more cracks when the cutters directly contacted the hard rock and energy consumption is high. Also, the dip an-gle of rock stratum has a great influence on the efficiency of rock breaking. When dip angle is close to 45° or 90°, cutters have high efficiency. Meanwhile, when cutter spacing is close to 70 or 120 mm, cutters have high efficiency. In addition, the cutter breaking rock was dominated by tensile failure and shear failure. The research findings can provide theoretical basis for the design of TBM cutter head and TBM construction in the composite rock strata.