中文摘要：

214国道位于青藏高原的东缘,1985-2012年期间的冻土勘察和地温监测资料表明,在河卡山至清水河439 km范围内的高山、滩地和沼泽化草甸地区分布着不连续和岛状多年冻土,公路实际穿越的多年冻土段累计里程约232.4 km,沿线绝大部分路段的地温高于-1.5℃,含冰量、冻土上限等多年冻土特征指标随地形、地貌变化剧烈.在分析上述资料的基础上,从冻土热稳定性和自然环境两个因素入手,采用突变级数法建立了多年冻土工程地质条件评价模型并对214国道多年冻土工程地质条件进行了定量评价.结果表明：214国道沿线冻土热稳定性普遍较差,自然环境多处于一般状态.除局部少冰、多冰冻土路段以外,沿线多年冻土工程地质条件总体处于较差或恶劣状态.与214国道病害调查资料进行比较后发现,路基病害一般发生在工程地质条件差的路段.这表明该评价结果比较准确的反映了沿线的多年冻土工程地质条件,对于现有214国道和新建共和-玉树高速公路的运营和维护具有重要的指导意义.

英文摘要：

National Highway 214 goes through the eastern part of the Tibetan Plateau. Investigation from 1985 to 2012 revealed that there were 439 km of the highway running between the Hekashan Mountain and the Qingshuihe village, including 232.4 km in permafrost regions, where the mean annual ground temperature was generally over - 1.5 ℃, ice content and permafrost table varied significantly with terrain and landform. Based on the permafrost investigation, engineering geological model for evaluating permafrost conditions is established by using the catastrophe progression method, which considered the thermal stability of permafrost and ambient environment. Evaluation based on the model shows that the thermal stability of permafrost is poor and environ- ment is in a normal state. Excluding some ice-poor section, geological conditions along the highway are in the bad and even worse state. It is found that the roadbed problems mainly occur in bad and worse geological condi- tions. The evaluation can effectively guide the operation and maintenance of National Highway 214 and the con- struction of Gonghe-Yushu Expressway.