Impact analysis of dust evolution pattern and determination of key ventilation parameters in highland highway construction tunnels

In order to study the influence of ventilation parameters on the ventilation of plateau highway construction tunnels, a highway tunnel construction section in Yunnan is taken as the research background, and Fluent software is used for simulation. The results of the study show that: under the conditions of press-in ventilation, the wind speed in the center of the vortex area in the wind flow field is smaller than the wind speed in the surrounding area, and with the diffusion of the flow field, the average wind speed in the tunnel section gradually decreases, and ultimately stabilizes at the level of 0.5 m/s. After blasting, the dust mass concentration on the return side of the tunnel is higher than that on the duct side. Dust with a particle size of 30 μm or more settled rapidly within 100 m from the boring face, while dust with a particle size of 30 μm or less gradually diffused outward under the action of the wind flow. In the vicinity of the tunnel boring face, reducing the distance from the air outlet to the boring face and increasing the air velocity can improve the dust removal effect. This conclusion can provide theoretical basis and certain guidance for the evolution of dust and dust prevention in the tunnel construction process in plateau area.