寒区高速铁路长大隧道温升问题研究

为了解决寒区高速铁路长大隧道由于列车运行导致隧道内环境温度的上升,从而对隧道安全运营产生不利影响的问题,针对多年冻土地区隧道围岩温度场具有导热与对流换热耦合边界并伴有相变的非稳态温度场的特点,联合应用有限体积法及有限单元法,进行围岩温度场的有限元分析。结果表明,对于寒区高速铁路长大隧道而言,列车的高速运行和特长隧道通风散热不畅所导致的隧道内热量集聚,将使隧道空间温度在未来几十年内缓慢上升,虽然数值不大;但引起了隧道周围冻土区温度场较大的改变,增大了冻土的融化范围,加深了地基土的融化深度,必将对隧道结构的稳定性及高速列车的运行安全造成不利影响。

Study on Temperature Increasing in Long Tunnels on High-speed Railways in Permafrost Regions

Due to the train running in the long tunnels on high speed railways in permafrost regions, the temperature in the tunnels increases, which will jeopardize the safe operation of the tunnels. In the paper, finite element analysis is made on the temperature field of the surrounding rock of tunnels in permafrost region on basis of the properties of the temperature field and by means of finite volume method and finite element method. Conclusions drawn are as follows: 1)For long tunnels on high speed railways in permafrost regions, the high speed running of the trains and the insufficiency of the ventilation system of the long tunnels cause heat accumulation in the tunnels, in turn cause the temperature in the tunnels to increase slowly in the future decades; 2)Although the temperature increase is insignificant, it causes great changes in the temperature field of the permafrost soil around the tunnels; 3)In this way, the thawing scope of the permafrost soil is enlarged, the thawing depth of the permafrost soil is increased, and the stability of the tunnel structures and the operation safety of the high speed trains are jeopardized.