青康公路多年冻土区路堤的临界高度

Critical Height of the Embankment in the Permafrost Regions along the Qinghai-Kangding Highway

青康公路运行３５ａ后，经沿线调查与钻探表明，在多年冻土区内，凡路堤高度低于０８ｍ的富冰地段，历年均有不同程度的热融、翻浆病害发生；凡路堤高度大于０８ｍ的路段则基本保持稳定．在全面分析路堤下冻土上限的升降规律基础上，并考虑目前区内冻土明显退化的现实与高级路面对路基变形的要求，提出高原多年冻土区修筑道路时，砂砾路面路堤高度应为１６ｍ，水泥混凝土路面路堤高度应为２０ｍ．

The survey and drilling investigation in the permafrost regions along the Qinghai-Kangding Highway, which has been operated for 35 years, indicate that the line where the height of the embankment is lower than 08 m suffers from frost boiling and thermokast to different extent every year, and that the line where the height of embankment was over 08 m maintains a steady state. Based on an overall analysis on the change in permafrost table under the embankment, after considering the fact that the permafrost in the area is degrading and the requirement of the deformation of the road surface of high quality, it is suggested that the height of embankment is 16 m for the gravel road, and 20 m for cement concrete road in the plateau permafrost regions.