不同围压条件下TBM刀具破岩模式的数值研究

为了研究不同围压条件下TBM刀具在掘进施工过程中的破岩机理，基于2-D离散单元法，利用UDEC仿真软件建立了双把TBM刀具侵入岩石的仿真模型。在此基础上设计了一组数值试验，成功地模拟出了不同围压条件以及不同刀间距下岩石裂纹生成，扩展和岩石破碎的全过程。仿真结果表明：TBM刀具作用下岩石存在四种基本的破碎模式，它们的出现与围压以及刀间距有关；破碎模式对刀具的破岩效率，岩石破碎块度均有影响；随着围压的增加，最优刀间距增大，但围压超过一定值后，最优刀间距反而减小。

Numerical study on modes of breaking rock by TBM cutter under different confining pressures

In order to research the rock breaking mechanism of TBM cutter in tunneling construction under different confining pressures, based on the 2-D discrete element method, a simulation model for breaking rock by two TBM cutters is established by using UDEC. On such a basis, a series of numerical tests are designed. The whole process of crack production and propagation is successfully simulated under different confining pressures as well as different cutter spacings. The simulated results show that there are four kinds of breaking patterns of rock which are related to the confining pressures and cutter spacings under the action of TBM cutters. Breaking patterns both affect the breaking efficiency and the rock fragment size. Along with the increasing confining pressure, the optimum cutter spacing increases, but when the confining pressure exceeds a certain value, it decreases inversely.