基于颗粒流模型的TBM滚刀破岩过程数值模拟研究

为了研究全断面岩石掘进机（TBM）盘型滚刀的破岩机制及其影响因素，采用颗粒流方法建立了岩石与滚刀的二维数值模型，实现了对TBM滚刀破岩过程的模拟。分析表明，滚刀的破岩过程可分为冲击挤压破碎、大量微裂纹生成、张拉性主裂纹扩展3个阶段，证实了滚刀破岩的挤压-张拉破坏理论。在滚刀侵入深度相同的前提下，随着刀圈刃角以及刃宽的增加，滚刀下的压碎区也相应增大，张拉性主裂纹数目增多，滚刀的破岩能力提高；与平刃刀圈相比，楔刃刀圈的“楔块劈裂”作用更加显著，使径向裂纹扩展得更快且更深入岩石内部。TBM滚刀对强度较高或较低岩石的破坏损伤较小，而对中等强度的岩石破坏损伤最为显著。

Research on numerical simulation of rock fragmentation by TBM cutters using particle flow method

In order to study the rock fragmentation mechanism and its influential factors, a numerical simulation method for simulating the rock fragmentation by the tunnel boring machine (TBM) cutters is proposed which is based on particle flow code (PFC) method. With PFC method, the two dimension numerical models of rock material and TBM cutters are created. The results show that the rock fragmentation process can be divided in 3 phases, which are fragmentation by impact and extrusion, appearance of micro cracks, extending of dominating tensile cracks. And this proves the extrusion-tension theory of rock fragmentation by TBM cutters. When the cutters have the same penetration depth, and the angle and width of cutter rings become larger, the crash zone and the number of dominating tensile cracks enlarge, which means the cutter’s fragmentation ability is enhanced. Compared with the plain cutter rings, the wedge effect of wedge cuter rings is more remarkable, which make the radial tensile cracks extend faster and deeper in rock material. The damage of medial strength rock by cutters is more remarkable than the high and low strength rock.