Cutterhead is the key part of full-face rock tunnel boring machine (TBM), the design method of mucking slot of TBM is directly related to its tunneling efficiency. In this paper, the coupling model of ballast and mucking structure of TBM is built used the discrete element method (DEM), and the simulation of TBM discharge ballast is made by PFC3D discrete element software. The simulation results show that, the number of particles generated is larger than the eliminated ones at the beginning of the mucking process, but with the change of time, the difference between the numbers of generated and eliminated particles is gradually reduced; the fluctuation of the number of particles within cutterhead is progressively smaller until it becomes stabilized, it fluctuates around the mean and the amplitude of fluctuation is no more than 100. The results in this paper can provide technical support for engineers.
