Study on Grading of Major Gas Hazard in Coal Mine Based on Z-number

In order to prevent and control gas disaster more pertinently, it is necessary to evaluate and control gas hazard scientifically. A grading evaluation model of major gas hazard was established, from the prospective of the possibility of gas accident, severity and emergency rescue. Combined with the actual situation of Sita Coal Mine of Tongmei Group, the analytical hierarchy process (AHP) and fuzzy comprehensive evaluation method based on Z-number fuzzy number were applied for calculation. The results show that the grade of major gas hazard in this coal mine is level 2, and once gas accident occurs, it may cause major accident, so the monitoring should be strengthened; the ranking of each evaluation index is gas prevention measure > staff awareness > number of workers > equipment level > … > medical conditions. Combined with the research results, a major gas hazard management and control model of coal mine is constructed, this model is practical and effective in the grade evaluation and management of gas hazard, but it still needs further study to refine the evaluation index system.