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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。
Permafrost areas with high temperature and high ice content are highly susceptible to disturbance from external conditions. In view of the characteristics of such frozen soil, a hot rod subgrade is proposed. According to the finite element method with phase transition heat conduction, the temperature field of normal embankment and hot rod embankment in the next 50 years along the Qinghai-Tibet Railway increased by 1.0 ℃, the temperature field was predicted and compared. The calculation results show that in the areas with annual average temperature of -3.5 ℃ or annual mean ground temperature of -1 ℃, the melting of the subterranean permafrost will occur during the 50-year service life of the Qinghai-Tibet Railway , The embankment will have greater thaw deformation, can not guarantee the stability of Qinghai-Tibet railway roadbed. Hot rod subgrade with active cooling effect, can better protect the frozen soil. The subgrade calculation structure shows that in the following 50 years the temperature rise of 1.0 ℃, the annual average temperature of -3.5 ℃ or surface temperature of -1.0 ℃ permafrost areas along the Qinghai-Tibet Railway, hot rod embankment can offset the warming climate Influence, you can ensure that subgrade permafrost does not thaw, which can guarantee the stability of subgrade.