Study on dust transport characteristics and ventilation system arrangement for high altitude tunnel construction
The purpose of this paper is to reduce the dust pollution generated by high-altitude Tunnel Boring Machines(TBM)in the construction process and further improve the ventilation and dust removal effect.This paper takes a plateau TBM construction tunnel as the research object,fluid simulation software Fluent was used to calculate the positions and pumping pressure ratio parameters of different supply air pipes and dust removal air pipes under long pressure and short pumping mode,and the simulation results were compared with empirical formulas to analyze the migration characteristics of dust in the tunnel.The results show that the dust in the long pressure and short suction ventilation system moves to the side of the dust removal duct under the action of airflow,most of which is discharged out of the tunnel through the dust removal duct,and a small part is gathered in the dust removal duct and the tunnel wall.The mechanical equipment in the tunnel has an impeding effect on the dust diffusion;when the air supply duct is 17 m away from the boring face,the dust content in the tunnel is larger in the latter part of the tunnel,and the dust quality concentration in the tunnel is smaller in the area 20 m away from the boring face;when the dust duct is 12 m away from the boring face,the dust mass concentration along the tunnel is relatively large;besides,the dust mass concentration in the area where the workers are concentrated is the highest,which is up to 65.44 mg/m3.The environment of the tunnel is better when the dust duct is at the position 6 m away from the boring face;the dust quality concentration along the tunnel is reduced by 50％when the pumping ratio is 0.8 compared with that of 0.5,and the dust removal effect reaches the best.The conclusion of the study can provide scientific reference for the design of ventilation schemes for large-section TBM construction in similar plateau areas.
safety and hygiene engineering technologyhigh altitudeTunnel Boring Machines(TBM)constructiondust migration
万方数据
维普
