Diffusion Characteristics of Airflow and CO in the Dead-End Tunnel with Different Ventilation Parameters after Tunneling Blasting

[Image: see text] After tunnel blasting, a large amount of CO will be produced and accumulated in the dead-end tunnel. If the ventilation discharge is not proper and the entry time into the dead-end tunnel is not appropriate, then it can cause workers to suffer from poisoning, hypoxia, and suffocation. Therefore, to understand the airflow and diffusion characteristics of CO in the dead-end tunnel after excavation and improve the working environment quality of the heading excavation tunnel, this paper uses numerical simulation and on-site verification to study the influence of different ventilation parameters on the airflow and CO diffusion characteristics in the dead-end tunnel after excavation and blasting. The research results show that the higher the air velocity of the duct, the smaller the distance between the duct and the working face, and the higher the hanging height of the duct, the easier it is for CO to be discharged from the dead-end tunnel. The larger the distance between the duct and the side wall, the more vortices there are in the dead-end tunnel and the more difficult it is to discharge CO from the tunnel. This study provides theoretical guidance for the research of the migration law of CO after tunnel blasting and has important value for ensuring a safe working environment and clean production in tunnel excavation.