多年冻土区碎石公路路堤降温效果的评价

Evaluation of Cooling Effectiveness in Fractured-Rock Highway Embankment in Permafrost Regions

为了评价多年冻土地区公路碎石路堤的自然对流降温效果,引入了通过碎石层与土层交界面的单位长度瞬态传热率和单位长度平均传热率两个参数,针对青藏公路的具体环境条件利用有限元数值方法进行了数值研究.结果表明:寒区碎石路堤降温效果可用单位长度瞬态传热率和单位长度平均传热率表征,单位长度瞬态传热率描述了碎石路堤自然对流降温效应的发生情况,而单位长度平均传热率描述了碎石路堤自然对流的降温能力.另外,它们还能够分区域评价碎石路堤降温效果.

In order to evaluate the cooling effectiveness of convection in the fractured-rock highway embankment in permafrost regions, the transient heat transfer rate and average heat transfer rate per unit length across the embankment-foundation interface were introduced. For the actual environmental conditions along the Qinghai-Tibet highway, a numerical investigation was performed using a finite element approach. The study result shows that the cooling effectiveness in the fractured-rock highway embankment can be represen-ted by the transient heat transfer rate and average heat transfer rate per unit length. The transient heat transfer rate per unit length may describe the cooling effect of natural convection in the fractured-rock embankment, and the average heat transfer rate per unit length can represent the cooling ability of natural convection in the fracturedrock highway embankment. They are also able to evaluate the cooing effectiveness of fractured-rock embankment across any part of a certain interface.