青藏高原多年冻土区铁路路堤变形特征研究

Study on Deformation Feature of Railway Embankment in Permafrost Regions on Tibet Plateau

路堤的稳定是公路、铁路等行车安全的保证。路堤变形通过路基—轨道—车辆大系统的相互作用而影响行车安全。冻胀、融沉是多年冻土地区路堤变形的重要形式。多年冻土区的路基变形问题是至今仍未彻底解决的一大难题。青藏铁路穿越 5 5 0km多年冻土区 ,为研究多年冻土区路堤变形特征 ,笔者对青藏铁路某试验段进行变形监测并对监测数据进行分析。结果表明铁路路堤的修建改变了多年冻土原来的水热平衡 ,天然冻土上限的变化导致路堤产生变形。同时 ,变形特征还受路堤边坡的坡向、降水量和地基土类型等因素的制约。在此基础上 ,提出几点减少多年冻土区铁路路堤变形的一些看法和建议。

Stability of the embankment is the guarantee of safe driving on railway and highway. Deformation of the embankment affects safe driving through the interaction among subgrade, track, and vehicle. Frost heave and thaw settlements are main forms of deformation of the embankment in permafrost regions. Deformation of the embankment in permafrost regions is still a problem unsolved. To understand deformation features of the railway embankment in permafrost regions on Tibet Plateau, some test section was monitored and the monitoring data were analyzed. The results show that the railway embankment construction changes the original water heat balance of the permafrost, and the change of permafrost table results in embankment deformation. Meanwhile, slope direction, rainfall and kinds of roadbed soil have significant effect on embankment deformation features. It is on this basis that several suggestions for decreasing the embankment deformation in permafrost regions were put forward.