The　rock　breakage　process　by　a　single　disc　cutter　and　the　ejection　speed　of　rock　fragments　are　simulated　using　three-dimensional　Finite　Element　Method　(FEM)　coupled　with　Smoothed　Particle　Hydrodynamics　(SPH)　method　in　this　paper.　Firstly,　the　rock　penetration　process　can　be　divided　into　three　stages　including　the　formation　stage　of　crushed　zone,　the　formation　stage　of　micro-cracks　and　the　propagation　stage　of　major　cracks.　Then,　during　the　rock　penetration　process,　three　different　zones　beneath　the　cutter,　namely　crushed　zone,　cracked　zone　and　intact　rock　zone,　can　be　distinguished　based　on　the　degree　of　cracking.　Finally,　the　ejection　speed　of　fragments　during　rock　penetration　process　is　obtained　using　FEM-SPH　method,　which　is　a　more　convenient　way　to　study　the　effect　of　the　harmful　ejection　of　rock　fragments　on　TBM　machine.　Moreover,　the　three-dimensional　numerical　results　are　in　good　agreement　with　experimental　observations.　(C)　2016　Elsevier　Ltd.　All　rights　reserved.