Study on Economic Wind Velocity and Basal Area of Ventilation Shafts of Tunnel

摘要

It is necessary to set up multiple ventilation shafts for tunnel segment ventilation especially in extra-long deep-buried tunnel. At the moment, the ventilation system of whole tunnel will be seriously affected by adjusting position or basal area of each ventilation shaft. This paper takes Niba Mountain Tunnel, a extra-long highway tunnel, as the object of study. Based on calculation method of normal operating ventilation of tunnel, economic wind velocity and economic basal area of ventilation shafts of three segments ventilation scheme for Niba Mountain Tunnel have been studied. Through a great variety of combination of different conditions and a lot of calculations, main conclusions are drawn as follows. It is the best both economically and technologically when 15m/s of design wind velocity is adopted in inclined shafts and connected aisles of Niba Mountain Tunnel. And while economic wind velocity of ventilation shafts is 15m/s, their economic basal area could be obtained. As a result, this study provides experience for the future related projects.