In order to reveal the effect of ventilation parameters and ground temperature on freezing damage in tunnels in cold regions,the three-dimensional unsteady numerical heat transfer control equations for the tunnel surrounding rock,lining,and airflow are developed based on heat transfer theory.The numerical heat transfer difference equations of different nodes are analyzed,and a three-dimensional temperature field numerical calculation model is established for tunnels in cold regions with high ground temperatures.The effect of mechanical ventilation velocity,mechanical ventilation time,and ground temperature on the anti-freezing length of tunnels in cold regions with high ground temperatures is studied based on numerical analysis.The results show that 1)without considering mechanical ventilation,the anti-freezing length of Zilashan tunnel will exceed 1200 m and decrease by about 100 m when the ground temperature increases by every 5℃.2)By considering the effect of mechanical ventilation,when the ground temperature is 10-30℃,ventilation at a speed of 2.5 m/s for 2.0 h per day can reduce the anti-freezing length by 215 m;the anti-freezing length decreases by about 20 m as mechanical ventilation velocity increases every 0.5 m/s under different ground temperatures,and the effect of ground temperature on the decay rate of anti-freezing length is slight;when the mechanical ventilation time is less than 2.0 h,increasing mechanical ventilation velocity under different ground temperature conditions has little effect on anti-freezing length.
关键词
寒区隧道/高地温/数值分析/机械通风/防冻长度
Key words
tunnel in cold region/high ground temperature/numerical analysis/mechanical ventilation/anti-freezing length
维普
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