Study on Ventilation and Dust Reduction Method for Long and Long Tunnel Construction of High-Speed Railway

Due to the long distance of long tunnel, the ventilation will be limited by the clearance size, which will affect the dust reduction effect. In view of this problem, a ventilation and dust reduction method for the construction of long tunnel of highspeed railway is proposed. The mathematical model of dust transport is established, the energy conservation equation of two-phase flow of gas and dust particles is obtained, and the law of dust transport in the tunnel is further analyzed. According to the optimal ventilation speed of tunnel construction ventilation, the ventilation parameters of long and long tunnels are calculated, and the long-distance multi-stage combined ventilation model is established, so as to determine the number and configuration of fans. The results show that the maximum dust concentration of this method is 0.6 mg/m3, which is 6.2 mg/m3 and 5.9 mg/m3 lower than that of pressure ventilation and extraction ventilation. Therefore, this method can achieve a better dust removal effect and meet the environmental requirements in the tunnel.