青藏铁路多年冻土区热棒路基温度场三维非线性分析

高温高含冰量的多年冻土地段,极易受外部条件的扰动而发生变化。针对此类冻土的特征,提出了热棒路基。根据带相变热传导有限元方法,对普通路基、热棒路基在未来50年青藏铁路沿线气温上升1.0℃情况下的温度场进行了预报分析和比较。计算结果表明,在年平均气温为-3.5℃或年平均地温为-1℃的地区,在青藏铁路50年的使用期内,普通路基在气温升高条件下路基下伏冻土都将发生融化,路基将会产生较大融沉变形,不能保证青藏铁路路基的稳定性。热棒路基具有主动冷却的作用,可以更好的保护冻土。路基计算结构表明,在未来50年气温上升1.0℃的条件下,在年平均气温为-3.5℃或地表温度为-1.0℃的青藏铁路沿线多年冻土地区,热棒路基可以抵消气候变暖的影响,可以保证路基下伏冻土不发生融化,从而可以保证路基的稳定性。

Three-dimensionanl Nonlinear Analysis of Thermal Regime of the Two-phase Closed Thermosyphon Closed Thermosyphon Embankment of Qinghai-Tibetan Railway

Warm and ice-rich permafrost is widely distributed along the Qinghai-Tibetan Railway,which is very sensitive to environmental changes.If permafrost under embankment thaws,the thaw settlement of permafrost may result in large embankment deformation and latent embankment instability.To protect permafrost from thawing,the two-phase closed thermosyphon is suggested.A three-dimensional numerical analysis of the thernal characteristics of both the common embankment and embankment with the two-phase closed thermosyphon is made.The numerical results indicate that better protection can be expected,with thermosyphon application.