TBM滚刀破岩的广义粒子动力学数值模拟

Numerical study of rock fragmentation by TBM cutters using general particle dynamics(GPD)

提出了一种新的无网格数值模拟计算方法——广义粒子动力学法(GPD),并在GPD算法中引入了粒子损伤理论。运用GPD方法,建立了TBM单滚刀、双滚刀作用下的完整岩体破岩模型,成功模拟了TBM滚刀破岩过程。通过与数值模拟结果及室内试验结果的对比分析,验证了GPD法模拟TBM滚刀破岩过程的有效性。同时,运用GPD方法建立了含节理岩体及高围压条件下岩体的TBM滚刀破岩模型,研究了节理及围压条件下TBM滚动破岩过程。得到了节理对TBM滚刀破岩效率的影响,既可能是促进作用又可能是抑制作用,高围压对TBM滚刀破岩过程中裂纹的起裂及扩展和破岩深度有较大的影响。

In this paper, a general particle dynamics（GPD） was proposed to reveal the mechanism of rock fragmentation by TBM cutters. The GPD method is regarded as a novel meshless numerical method by introducing the particle failure criterion. The numerical models were established for intact rock fragmentation by a single TBM cutter and double TBM cutters using the GPD method, and the whole processes were successfully investigated. It was found that numerical results obtained by the GPD method were in good agreement with experimental results and previous numerical results, which verified the validity of GPD method for rock fragmentation by TBM cutters. Moreover, the GPD method was adopted to establish numerical models by considering the influences of joints and high confining pressure on rock fragmentation by TBM cutters. The results showed that the inclination angle of joints significantly affected the efficiency of TBM cutting, and the effects were quite different with increasing the inclination angle of joints. The high confining pressure greatly influenced the characteristics of crack initiation, propagation and even the depth of rock fragmentation by TBM cutters. Therefore, the GPD method demonstrates great potential to investigate rock fragmentation by TBM cutters.