execute an efficient blasting sequence, and areas of low fragmentation, overbreak or even unexploded holes (misfires) can be generated, which negatively affects the performance of the cycle. Therefore, a systematic process of measurement and analysis of the real trajectory of the cut holes was implemented, with the aim of: • Quantify angular and linear deviations from the designed mesh. • Identify deviation patterns associated with geological conditions or recurrent operating factors. • Adjust the detonation sequencing, allowing the assignment of differentiated delay times per hole, according to its actual location, and thus recover the logic of the shot. Figure 2 presents a scatter plot representing the measured trajectories of the holes, compared to their theoretical orientation. Figure 3 also shows the percentage of deviation associated with each drill, key information for the calibration of the blasting design and the optimization of the overall performance of the face. Figure 2 – Dispersion of drilled holes at cut. Figure 3 – Percentage of deviation by number of holes. Table 1 – Number of holes and percentage of deviation. Deviation Test 1 Test 2 Test 3 Holes No. % Deviation Holes No. % Deviation Holes No. % Deviation 0.0 – 0.25m. 4 36 3.7% 6 55 1.8% 8 73 1.6% 0.25 – 0.5m. 5 46 4.5% 5 45 4.5% 3 27 4.3% 0.50 – 1.0m. 2 18 7.6% 0 0 0 0 0 0 R1 R2 R3 R4 R5 R6 R7 A1 A2 A3 A4 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 Variation Y (m) Variation X (m) 6 5 0 55% 45% 0% 0% 10% 20% 30% 40% 50% 60% 0 1 2 3 4 5 6 7 0.0 - 0.25m. 0.25 - 0.5m. 0.5 - 1m. Percentage N°Holes Number of deviated drill holes
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