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

作　　者：Cong Li Zhongan Jiang Guoliang Zhang Xue Feng Fabin Zeng 

机构地区：[1]College of Civil and Resource Engineering,University of Science and Technology Beijing,Beijing,100083,China [2]NHC Key Laboratory for Engineering Control of Dust Hazard,University of Science and Technology Beijing,Beijing,100083,China

出　　处：《Particuology》2023年第4期82-95,共14页颗粒学报（英文版）

基　　金：the National Natural Science Foundation of China(grant No.51874016).

摘　　要：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 Computa-tional 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 influ-encing factors on dust diffusion in the shotcrete operation area.The results show that the dust gener-ation 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 be-comes 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.

关 键 词：High-altitude tunnel SHOTCRETE Dust diffusion Numerical simulation Ventilation system 

分 类 号：X51[环境科学与工程—环境工程]