多年冻土区青藏公路路基边界温度及计算模型研究

温度边界是冻土工程模拟中重要的边界条件之一。依据青藏公路多年冻土段不同走向路基断面表层温度的连续观测数据，分析了青藏工程走廊内路基实测的边界温度特征。结果表明：走向为W8° S的断面阴阳坡温差最大为5.81 ℃，走向为W34°S的断面坡面温差为5.68 ℃，走向为W86° S度的断面坡面温差为1.38 ℃，说明高原上无论路基走向如何，路基两侧坡面都存在温度差异，因此，两侧必须采取差异设计，以减少路基温度的不对称。同时，根据路基接收太阳能辐射反演路面及边坡表面温度，提出了工程热边界的简化计算模型，并将模型计算结果与实测数据进行对比，两者吻合较好。

Study on the temperature boundary of embankment and its calculation model of the Qinghai-Tibet Highway in permafrost area

The temperature,which is the most important boundary condition for continuous action,is very close to the evaluation of thermal stability.Based on the observation data of the surface temperature (5 cm) in different section along Qinghai-Tibet engineering corridor,boundary temperature characteristics are analyzed in the paper.According to the results,Thetemperature differences between north-faced and south-faced slope are 5.81 ℃,5.68 ℃ and 1.38 ℃ with roadbed trends of W8° S,W34°S and W86° S,respectively,which indicating that there exist temperature differences between the north-faced and south-faced slope of the highway regardless of roadbed trend.Hence,the subgrade must take different designs on both sides of the embankment to reduce the asymmetry of temperature.Furthermore,based on retrieving the ground surface temperature by the surface absorption radiation,a simplified calculation model of engineering temperature boundary is proposed,which shows a good agreement with observation data and it can provide important boundary conditions for numerical simulation.