Dust pollution during shotcrete process in high-altitude tunnel based on numerical simulation--颗粒学报PARTICUOLOGY

Li, C., Jiang, Z., Zhang, G., Feng, X., & Zeng, F. (2023). Dust pollution during shotcrete process in high-altitude tunnel based on numerical simulation. Particuology, 75, 82-95. https://doi.org/10.1016/j.partic.2022.05.012

Dust pollution during shotcrete process in high-altitude tunnel based on numerical simulation

Cong Li ^{a b}, Zhongan Jiang ^{a b *}, Guoliang Zhang ^{a b}, Xue Feng^{a b}, Fabin Zeng ^{a b}

a College of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing, 100083, China
b NHC Key Laboratory for Engineering Control of Dust Hazard, University of Science and Technology Beijing, Beijing, 100083, China

10.1016/j.partic.2022.05.012

Volume 75, April 2023, Pages 82-95

Received 26 April 2022, Revised 22 May 2022, Accepted 23 May 2022, Available online 7 June 2022, Version of Record 1 August 2022.

E-mail: jza1963@263.net

Highlights

• The dust production mechanism of shotcrete was summarized.

• The dynamic diffusion of dust under different conditions was visualized.

• The movement law of fine dust particles in high-altitude tunnels was analyzed.

• The correlation values of the influencing factors on dust diffusion were investigated.

Abstract

The surrounding rock needs shotcrete support after drilling and blasting excavation in the tunnel; the high concentration of dust generated in the process will endanger workers’ occupational health. Therefore, to ensure the cleanness and safety of the tunnel construction process, a full-scale model of the tunnel was established based on field data of a high-altitude tunnel of the Sichuan-Tibet railway. The dust production mechanism is summarized by combing the whole process of shotcrete. The Computational Fluid Dynamics (CFD) method was used to study the diffusion and transport of dust under different conditions. The grey relational analysis was applied to investigate the correlation values of the influencing factors on dust diffusion in the shotcrete operation area. The results show that the dust generation mechanism of shotcrete includes the sudden change of particle velocity in the jet area leading to escape and particle impact dust generation, where fine dust is easily dispersed in the tunnel. During continuous dust production, the dust concentration is higher near the wet spraying machine and on the backflow side of the working face. Increasing the air supply volume and shortening the distance between the air duct and the working face is conducive to diluting the dust concentration in the tunnel. In the high-altitude environment, the dust concentration in the tunnel decreases, the diffusion distance becomes smaller, the settlement proportion of dust particles increases, and the risk of secondary pollution increases. The simulation results and the field measurement data are consistent, which can provide theoretical support for the construction site dust control.

Graphical abstract

Keywords

High-altitude tunnel; Shotcrete; Dust diffusion; Numerical simulation; Ventilation system

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