青藏铁路高温细粒冻土地区站场路基实体试验研究

青藏铁路站场路基比一般铁路路基宽度大,为此,在清水河高温细粒土地段进行了专门的现场试验研究。通过采用不同深度处地温场变化、上限变化、阴阳坡温度变化以及积温等分析方法,对该试验段3个冻融循环过程中监测到的温度场分析,并与普通路基的温度场数据进行对比。通过分析可以看出,站场路基下人为上限的上升幅度比普通路堤要大,路基表面以下同样深度处的地温,站场路基下的地温要低于普通路堤下的地温,因此路堤宽度较大的站场路基对多年冻土的保温效果比普通宽度的路堤好。由变形观测数据看出,冻胀量较小,变形主要为沉降变形,路堤阳坡冻胀板的变形量要大于路堤阴坡相应位置的冻胀板变形量。阳坡上层冻胀板最大沉降量是0.241 m;下层冻胀板最大沉降量0.237 m,且随着时间推移,变形趋于稳定。

In-situ study of permafrost embankments of Qinghai-Tibet Railway Station

Owing to the wider embankments of the station yard of Qinghai-Tibet Railway than the ordinary ones, a special in-situ test study was performed for the high temperature fine-grained permafrost section of Qingshuihe. By the variation of temperature fields at different depths of embankments, variation of frost table, temperature distribution of shaded side and sunny side and accumulated temperature, 3 groupes of frost-thaw test data were analyzed and compared with those of general embankments. It was found that the rising amplitude of frost table of station embankments was larger than that of the ordinary embankments, and at the same depth, temperature of station embankments was lower than that of ordinary embankments. That is, station embankments were more effectively protected from permafrost than the ordinary embankments. From the data of deformation, swell deformation was small, the main deformation was settlement. The settlement of sunny side was larger than that of shaded side. In sunny side, deformation of the upper layer was 0.241 m, and that of the lower layer was 0.237 m, and with the in crease of time went on, the deformation came to stable.