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Research on Ventilation Design for Construction of Super-large Diameter Slurry Shield Tunnel
(1. China Railway Siyuan Survey and Design Institute Group Co., Ltd., Wuhan 430063; 2. National-Local Joint Engineering Research Center of Underwater Tunneling Technology, Wuhan 430063)
Abstract In this study, based on the ventilation design of a large diameter slurry shield tunnel under construction, the computational fluid dynamics software (ANSYS Fluent) is used to simulate and analyze the ventilation effect of tunnel construction. The accuracy of calculation results of the numerical simulation model is verified through onsite measurements, and the flow field distribution and the airflow movement law under ventilation conditions are summarized. A comparative study is conducted on the influence of three different ventilation parameters such as wind speed at the air duct outlet, air duct diameter, and position of air duct outlet, and an optimization plan for ventilation parameters is proposed. The results show that the wind speed distribution in the ventilation flow field of the tunnel exhibits the following characteristics: the wind speed on the return air side is generally larger than that on the inlet air side, and the wind speed on the upper part of the tunnel is generally less than that on the lower part. Increasing the wind speed at the outlet of the air duct is the most significant in improving the ventilation effect of tunnel construction; After adopting the optimized plan, the average wind speed at the tunnel center can be increased by about 59.3%, and the velocity of airflow in each working area can reach the construction ventilation standard of 0.15 m/s or above, which can economically and efficiently improve the ventilation effect in the working area of the shield section of the tunnel.
Abstract：
In this study, based on the ventilation design of a large diameter slurry shield tunnel under construction, the computational fluid dynamics software (ANSYS Fluent) is used to simulate and analyze the ventilation effect of tunnel construction. The accuracy of calculation results of the numerical simulation model is verified through onsite measurements, and the flow field distribution and the airflow movement law under ventilation conditions are summarized. A comparative study is conducted on the influence of three different ventilation parameters such as wind speed at the air duct outlet, air duct diameter, and position of air duct outlet, and an optimization plan for ventilation parameters is proposed. The results show that the wind speed distribution in the ventilation flow field of the tunnel exhibits the following characteristics: the wind speed on the return air side is generally larger than that on the inlet air side, and the wind speed on the upper part of the tunnel is generally less than that on the lower part. Increasing the wind speed at the outlet of the air duct is the most significant in improving the ventilation effect of tunnel construction; After adopting the optimized plan, the average wind speed at the tunnel center can be increased by about 59.3%, and the velocity of airflow in each working area can reach the construction ventilation standard of 0.15 m/s or above, which can economically and efficiently improve the ventilation effect in the working area of the shield section of the tunnel.
HU Weidong1,
2
.Research on Ventilation Design for Construction of Super-large Diameter Slurry Shield Tunnel[J] MODERN TUNNELLING TECHNOLOGY, 2023,V60(5): 186-194
2023, Vol. 60 