Ø equivalent = equivalent relief diameter (mm) L = Drill Length (m) Substituting L = 8.0 m, we get: Ø equivalent = 110 + 15.4 x (8) = 233.2mm With this value, the optimal number of relief holes is determined by equation (2): where: Ø equivalent = Ø relief x (2)√ (2) Ø relief = 102 mm n = number of relief holes Clearing n, the value of 5.2 ≅ 6.0 is obtained, which satisfies the geometric condition of the relief necessary for the evaluated drilling length. Additionally, the relative empty volume (VR) generated by the relief and loaded holes was analyzed in relation to the effective breaking area. The expression used is shown in equation (3): = N° Holerelief x (π x( ∅ relief 2 ) 2 )+ N° Holebreak x (π x( ∅ break 2 ) 2 ) AREACut− (N° Holerelief x (π x( ∅ relief 2 ) 2 )+ N° Holebreak x (π x( ∅ break 2 ) 2 )) (3) VR= 7 x (π x( 102mm 2 ) 2 ) + 4 x (π x( 54mm 2 ) 2 ) (0.90 0.90 ) − (7 x (π x( 102 2 ) 2 ) + 4 x (π x( 54mm 2 ) 2 )) This calculation yielded a value of VR≈9.0% considered acceptable to ensure effective cut without compromising contour stability. The critical separation between loaded holes was also estimated, which represents the maximum permissible distance without loss of continuity at the break of the massif. This was obtained using equation (4): = 2 ∅ ( 0 )( 100 ) (4)
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