Water migration in subgrade soil under seasonal freeze-thaw cycles in an alpine meadow on the Qinghai-Tibet Plateau  

作　　者：WU Guan-qing XIE Yong-li WEI Jin YUE Xia-bing 

机构地区：[1]School of Highway,Chang'an University,Xi'an 710064,China

出　　处：《Journal of Mountain Science》2022年第6期1767-1781,共15页山地科学学报（英文）

基　　金：supported by the Fundamental Research Funds for the Central Universities(Grant No.310821173701);Natural Science Basic Research Program of Shaanxi(Grant No.2020JQ-379)。

摘　　要：Highway frost heave and thawing settlement caused by water migration towards the freezing front and ice lens development is widespread in the alpine meadow area of the southeast QinghaiTibet Plateau(QTP). A laboratory experiment on a highway reconstruction and expansion project in the QTP was carried out in this work to analyze the effects of fine particle content, initial water content, and the number of freeze-thaw cycles(FTCs) on frost depth, temperature gradient(Grad T), total water intake, and water intake flux. Based on the results of the laboratory experiment, a modified model of migration potential related to fine particle content, freeze-thaw history, and freezing time was established. The results show that, with the increase of fine particle content, the frost depth of soil decreases, the curve of total water intake over time is transformed from an Sshape to an arch, and the curve of water intake flux over time is transformed from a peak shape to descending shape. The variation trend of migration potential with freezing time and the freeze-thaw history is the same as that of water intake flux with freezing time and freeze-thaw history. The variation trend of soil intake flux can be used as a reference to determine the variation trend of soil migration potential. This study provides a reference for the design and construction of highway subgrade in the alpine meadow area of the QTP.

关 键 词：Water migration Seasonally frozen ground Freeze-thaw cycles Laboratory experiment Migration potential model Qinghai-Tibet Plateau 

分 类 号：U416.1[交通运输工程—道路与铁道工程] S812.2[农业科学—草业科学]