Application of Thermal Pressure Ventilation Technology in Extra Long Construction Tunnel with High Ground Temperature

Abstract

Abstract The feasibility of thermal pressure ventilation technology for ventilation and cooling of extra long construction tunnel with high altitude and high ground temperature was discussed. A physical model was built with a proportional factor of 1:1 based on the design documents of Zilashan tunnel in China. The CFD model considering buoyancy effects was used to evaluated the influence of the initial rock temperature, the insulation performance of the left tunnel and the outdoor air temperature on the effect of thermal pressure ventilation. Results show that the effect of thermal pressure ventilation increases by 12.2%, and the effect of cooling enhances by 3.7% when the left tunnel has no insulation. Compared with the initial rock temperature, the outdoor air temperature has a greater influence on thermal pressure ventilation. When the initial rock temperature is below 54 °C, outdoor air temperature is below 17.5 °C and the left tunnel has no insulation, thermal pressure ventilation technology is feasible for ventilation and cooling of Zilashan tunnel with a shaft of 450 m height. The thermal pressure ventilation technology provides a reference for other construction tunnel projects as a design of ventilation and cooling.