Penetrating granite specimens with different wedge cutters by changed RMT-150C system which is specially produced for indentation,and using DISP acoustic emission location system to research rock damage and physical deterioration.Acoustic emission test is an effective method to study the microscopic mechanism of rock fragmentation by tunnel boring machine(TBM) cutters.Testing results show that: rock breaking is the macro-phenomenon of internal microcrack's initiation and development.There is a realistic cor...