NFC Africa Mining PLC
In this paper, numerical simulation analysis of two Undercut schemes was carried out using Ansys/LS-DYNA software to ensure the safe and efficient production of the mine. According to the analysis, the final section size of the raise meets the design requirements, and the section of the cavity shows the characteristics of large at both ends and small in the middle, which has a good Undercutting effect; comparing the peak vibration speed at each point shows that the blasting vibration control effect of Option 1 (Nine large holes plus four small holes hollowing method) is significantly better than that of Option 2(nine-hole hollowing method). Option 1 should be used when the offset rate is large and the surrounding rock needs to be protected; Option 2 should be used when the offset rate is small and the surrounding rock does not need to be protected. Both options achieved the expected Undercutting results in the mine field tests. The results of the study provide a reasonable solution for the process of disposable blasting well.