• The CFS-TSCF method enables low-energy hard rock breaking by creating a controllable free surface that redirects stress, achieving predominantly tensile (>50%) fracturing.
• The method transforms triaxial compression into a directional tension-dominated stress path, guiding fractures along low-energy channels and reducing tool wear.
• Multi-scale validation (lab AE tests, DEM simulations, field trials) confirms the mechanism and practical applicability in hard rock with UCS >200 MPa.
• Field trials demonstrate an average mining efficiency of 52.03 t/h with controllable blocky spalling, offering a safe and continuous alternative to drilling and blasting.