Comparison of ventilation methods used during tunnel construction.

Ensuring adequate ventilation during tunnel construction is a critical issue that directly affects construction efficiency. A good ventilation environment can effectively guarantee the construction progress. In this paper, by repeatedly selecting the flow field simulation parameters and continuously summarizing the calculation methods, a reasonable model is selected to simulate the tunnel engineering. Specifically, the eddy current zone near the working face is obtained by analysing the flow field of forced ventilation tunnels. Furthermore, we analyse the dispersion and accumulation of harmful gases in the tunnel. The CO concentration at typical locations in the tunnel is also examined in order to determine areas with the lowest likelihood of harmful gas discharge. We then propose adding a jet fan to the tunnel to create an extraction plus ventilation tunnel. Simulation results reveal that the addition of a jet fan causes eddy currents that improve the extraction of harmful gases, thereby greatly reducing ventilation time and increasing efficiency. The results of the model can effectively guide the actual project, and help them save the construction time. [ABSTRACT FROM AUTHOR]