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在考虑未来50 a气温上升1℃的情况下,通过数值模拟来研究通风管-块石(封闭)新型复合路基的降温效果.结果表明:普通路基下冻土上限从第1年的-1.86 m下降到第50年的-4.85 m;50 a后,普通通风管路基和封闭块石路基下部多年冻土的0℃等温线分别位于天然地表下-0.89 m和-0.22 m处,通风管-块石(封闭)路基下部0℃等温线在50 a内始终高于天然地表,第50年的0℃等温线位于天然地表之上0.04 m处;在暖季,通风管-块石(封闭)路基与天然地表交界面的正热流密最小,普通通风管路基中的通风管热流密度为正,而通风管-块石(封闭)路基中的通风管热流密度为负,这表明复合路基中封闭块石弥补了通风管暖季吸热的缺陷;在高温高含冰量地区推荐使用通风管-块石(封闭)路基作为公路路基结构.
Considering the temperature rise of 1 ℃ in the future 50 °, the cooling effect of the ventilation ducts-block stone (closed) new composite subgrade is studied by numerical simulation.The results show that the upper limit of the permafrost under common embankment decreases from -1.86 m Down to -4.85 m in the 50th year. After 50 years, the 0 ℃ isotherms of permafrost in the ordinary ventilation subgrade and the closed subgrade were located at -0.89 m and -0.22 m below the natural subsurface, respectively. The ventilation pipe-block The 0 ℃ isotherm in the lower part of the stone (enclosed) subgrade is always higher than the natural surface within 50 days, and the 0 ℃ isotherm in the 50th year is located at 0.04 m above the natural surface. In warm season, the ventilation pipe - block stone The positive heat flux at the interface with the natural ground surface is the smallest, the heat flux density of the ventilation duct in the common ventilation duct is positive, and the heat flow density of the ventilation duct in the ventilation duct - block stone (closed) is negative, indicating that the closed block Stone makes up for the shortcomings of heat pipe endothermic heat pipe; in the high temperature and high ice content area recommended ventilation pipe - stone (closed) subgrade as a highway subgrade structure.