Flaws　such　as　faults,　joints,　and　bedding　planes　often　exist　in　natural　rock　masses,　which　pose　significant　safety　hazards　for　tunnel　excavation.　We　conducted　a　series　of　experimental　tests　to　analyse　the　effect　of　the　different　flaw　occurrences　(intact,　open-flaw,　and　filled-flaw)　on　the　rockburst　mode　around　a　horseshoe-shaped　tunnel.　The　destruction　was　monitored　by　continuous　photo　imaging　(captured　inside　the　tunnel)　and　acoustic　emission　(AE)　monitoring.　Test　results　show　that:　1)　Under　different　flaw　occurrences,　the　rockburst　mode　is　different.　mainly　for　strain　rockburst　and　fault　slip　rockburst　2)　Strain　rockburst　produces　more　tensile　cracks　in　the　initial　stage　(I　and　II)　and　more　shear　cracks　in　the　later　stage　(III,　IV　and　V).　However,　the　fault　slip　rockburst　produces　shear　cracks　from　the　beginning　to　the　end.　3)　The　filled　material　inside　the　flaws　can　significantly　enhance　the　stability　of　the　surrounding　rock　and　also　inhibit　the　development　of　fault　slip　rockburst.　The　rockburst　modes　and　mechanisms　under　different　surrounding　rock　conditions　have　been　verified　by　PFC.　©　2024　Elsevier　Ltd