寒区长大隧道温度实测与仿真

基于现场实测数据对寒区长大隧道内温度的变化规律进行了分析,基于数值仿真分析对不同环境气温、围岩原始地温、自然风速、列车运行速度和频率条件下隧道洞内温度场和冻结深度的变化规律及保温层的适用范围进行了研究.研究结果表明:若环境气温或围岩原始地温低,自然风速大,或列车运行速度大和运行频率高,则洞内可能出现负温分布,所以寒区长大隧道结构防寒不应仅在洞口段;保温层法不能完全解决寒区长大隧道洞口保温问题,当环境气温低于15℃,持续冻结时间超过45d时,需要采取主动保温措施.

Temperature measurement and simulation of long tunnel in cold region

The change rules of temperature field of long tunnel in cold region is analyzed based on measured data,and the change rules of temperature field,frozen depth of tunnel and the application scope of thermal insulation layer under different ambient temperatures,original ground temperatures of surrounding,natural wind speeds,train running speeds and train running frequencies are studied based on numerical analysis.The results show that the tunnel may appear negative temperature distribution in cases that the ambient temperature or the original ground temperature of surrounding rock is low,the natural wind speed,the train running speed or the train running frequency is high,therefore,the cold-proof measures of long tunnels in cold regions should not be used only in the entrance.And thermal insulation layers have been unable to meet cold-proof requirements of long tunnels in cold regions when the ambient temperature is less than 15 ℃ and the duration of freezing is more than 45 d,in this case,it is necessary to take active heat preservation measures.