Backflow Simulation Combined with Laser Visualization Regarding Dust Removal Effect during Tunnel Construction

Abstract The removal of respirable dust and harmful gasses in tunnel construction is a crucial topic for the occupational safety of tunnel construction workers. Mechanical ventilation is the most widely used method to remove the dust at present. But respirable dust is difficult to remove by sedimentation because of the small particle size. The setting of airflow rate in the ventilation duct and the distance between the ventilation duct and the working face highly affect the efficiency of dust removal. When the ventilation duct is far away from the working face, there is often no effective air flow reaching the working face due to the backflow. So, understanding the airflow distribution in the tunnel is necessary to evaluate dust removal effects. This contribution simulates the airflow of the Zentrum am Berg (ZAB) tunnel through numerical simulation and also sets up the laser device to visualize the air flow. The backflow sections from numerical simulation and laser visualization are verified and compared with each other to provide guidance on dust removal effect optimization during tunnel construction.