A study on the dust control effect of the dust extraction system in TBM construction tunnels based on CFD computer simulation technology

In order to control dust in a tunnel boring machine (TBM) construction tunnels, this paper, in combination with field measurements, applies CFD computer simulation technology to study the dust control effect of TBM construction tunnels under different dust extraction flow rates. Firstly, the dust extraction system is closed, and the result of the simulation show that the dust diffuses to the entire TBM working area within 181 s, indicating the necessity of having a dust extraction system in the tunnel. Secondly, the dust extraction system is open and under the original dust extraction flow rate of Q(e) = 8 m(3)/s, the overall dust diffuses to the entire working area L-o = 130 m, and the full-face dust diffusion distance is L-f = 47.54 m. Then the study was carried out with the setting of 2 m(3)/s <= Q(e) <= 14 m(3)/s. The results show that: when Q(e) <= 8m(3)/s, the full-face dust diffuses to 47.54-71.84 m; when Q(e) > 8m(3)/s, the full-face dust can be controlled at 42.81-46.34 m; and when Q(e) = 8 m(3)/s, the full-face dust control effect is better, and the average dust concentration in the tunnel is as low as 12.25 mg/m(3), indicating that the original dust extraction system has a better design. The field measurement results verify that the CFD computer simulation results are accurate. (C) 2019 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.