冰-水相变对寒区隧道动态温度场影响研究

为了揭示冰-水相变对寒区隧道动态温度场的影响,通过建立隧道有限元模型,对比分析考虑相变与否两种情况下隧道温度场的动态变化,研究隧道在内部气温变化作用下的冰-水相变发展过程。研究表明:围岩内部温度随深度增加而升高,年变化幅度逐渐减小,变化相位逐渐滞后;考虑冰-水相变后,隧道温度场年动态变化过程改变较大,温度年变化幅度显著减小;在外界低温的作用下,主洞与导洞部位均有结冰现象,衬砌和围岩内部在1月份开始结冰,4月份之后完全冻结区消失,仅在衬砌和围岩存在冰水混合区,至7月份完全解冻,解冻后重新冻结的月份为10月份,之后冻结范围逐渐扩大,全年冻结发展最快的时间为11月份。

Study on the Effect of Water-ice Phase Change on Temperature Field of Tunnel in Cold Region

In order to reveal the effect of ice-water phase change on the dynamic temperature field of tunnel in cold region,a finite element model of tunnel is established to analyze the dynamic variation of tunnel temperature field with and without ice-water phase change,and study the development process of ice-water phase change under the effect of variation air temperature.The results show that with the increase of depth,the internal temperature of surrounding rock increases,the yearly variation amplitude decreases,and the variation phase delays gradually.With phase change of ice-water considered,the yearly dynamic variation process of tunnel field changes greatly,and the yearly variation amplitude of temperature decreases significantly.Both the main tunnel and the pilot tunnel are frozen subject to low air temperature,the lining structure and surrounding rock begin to freeze since January,the complete frozen zone disappears after April and only the ice-water mixing zone remains in the lining and surrounding rock.The frozen zone completely thaws in July and refreezing of lining and surrounding rockstarts in October,and extends gradually afterwards.The fastest development of frozen zone in a year appears in November.