草木沟隧道温度场实测与分析

Measurement and Analysis of Temperature Field in Caomugou Tunnel

为了探究寒区隧道贯穿运行后温度场的演化规律,以吉图珲铁路草木沟隧道为研究对象,根据现场温度实测数据,采用ANSYS有限元软件建立等比例隧道温度场模型。基于热传导理论分析影响温度场演化的主要因素,采用控制变量法计算得出不同冻结期、有无列车风及不同外界气温条件下隧道纵向和径向温度场的分布规律。研究结果表明:隧道实测断面温度呈正弦规律分布,距衬砌表面越远,温度振幅越低;隧道全线冻结期内仅有280 m温度处于0℃以上,故需对隧道全线进行防寒保温措施;隧道洞口段冻结深度与冻结时长、外界气温密切相关,冻结时间越长冻结深度越深,极端气温下洞口冻结深度最高可达8.2 m;相较于自然风的影响,不同列车风速对冻结深度影响较小,但列车运行情况下隧道径向冻结深度平均增加了0.19 m,因此列车风的影响不容忽视。研究成果可为草木沟隧道冻害整治提供理论数据支持。

In order to explore the evolution law of temperature field after tunnel running through in cold area,taking Caomugou Tunnel of Jilin-Tumen-Hunchun railway as the research object,according to the field temperature measured data,the equal proportion tunnel temperature field model was established by using ANSYS finite element software.Based on the heat conduction theory,the main factors affecting the evolution of temperature field are analyzed,and the control variable method was used to calculate the distribution law of longitudinal and radial temperature field of tunnel under different freezing periods,with or without train wind and different external temperature conditions.The results show that the measured section temperature of the tunnel is sinusoidal,and the farther away from the lining surface,the lower the temperature amplitude.During the freezing period of the whole tunnel,the temperature of only 280 m is above 0℃,so cold proof and thermal insulation measures shall be taken for the whole tunnel.The freezing depth of tunnel portal section is closely related to the freezing time and external temperature.The longer the freezing time,the deeper the freezing depth.Under extreme temperature,the freezing depth of tunnel portal can reach 8.2 m;Compared with the influence of natural wind,different train wind speeds have little influence on the freezing depth,but the radial freezing depth of the tunnel increases by 0.19 m on average under the condition of train operation,so the influence of train wind can not be ignored.The research results can provide theoretical data support for the frost damage regulation of Caomugou tunnel.