Research on safety assessment of open pit blasting based on blind number theory and improved cloud model

To make the blasting safety assessment of open pit mines more scientific and enhance its reliability of the assessment results, blind number theory and improved cloud model were introduced to improve safety assessment of open pit blasting. In this paper, a comprehensive evaluation indicator system of such safety assessment was formed from such three aspects as safety management, organizational design, and on-site construction after 15 typical influencing factors were selected. Based on the blind number theory, the blind number matrix was established to determine the comprehensive index score, which improved the traditional qualitative index assignment method. The comprehensive weight of the index was determined by the game theory, and the comprehensive certainty was calculated based on the principle of the cloud model, thereby determining the comprehensive evaluation of blasting safety in open-pit mines on the maximum membership degree principle. Three open-pit mines were taken as an example to discuss their blasting process and assess the model’s blasting safety levels. The results showed that their blasting safety levels were Ⅳ, Ⅳ, and V levels in consistent with the actual blasting site. By comparing the evaluation results of fuzzy mathematics and unascertained measures, the blind number theory and improved cloud model can reduce the blindness of the evaluation process, and the evaluation results are more rigorous and conservative. This verifies the superiority and applicability of the model in the safety evaluation of open-pit mine blasting, reflects the research value, and can provide a theoretical basis for the safety evaluation and identification of weak links in open-pit mine blasting.