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The impact of wind-blown sand on crushed-rock embankment along the Qinghai-Tibet Railway (QTR), China

Ruiping Zu, Zhilin He, Jianjun Qu, Yumei Zong, Kecun Zhang
Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou, Gansu Province, China

The impact of wind-blown sand on crushed-rock embankment along the Qinghai-Tibet Railway (QTR), China

Ruiping Zu, Zhilin He, Jianjun Qu, Yumei Zong, Kecun Zhang

Key Lab. of Desert and Desertification, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, Gansu Province, China

 

Abstract: The crushed-rock embankment, widely used along the Qinghai-Tibet Railway (QTR), has been proved to have active cooling effect and thus could effectively protect permafrost beneath the roadbed. However, with the increasing degree of desertification in Tibetan Plateau, the crushed-rock embankments along the QTR were frequently filled up or buried by wind-blown sand and in addition, the impact of wind-blown sand on the cooling effect of the crushed-rock embankment has not yet clearly addressed. This paper simulated the ground temperature variations of the frozen earth beneath the crushed-rock layer under different situations through indoor experiment. The results show that the bare crushed-rock layer has good cooling effect on underlying frozen earth, but after filled or covered by windblown sand, the cooling effect will significantly weaken or even disappear, and the thicker the windblown sand layer, the higher the ground temperature of frozen earth. This indicates that the windblown sand could be a potentially serious threat to the crushed-rock embankment along the QTR in the long term. It is urgent to establish comprehensively sand-prevention system in some key places in order to protect the crushed-rock embankment from windblown sand damage more effectively.

 

Key words: Wind-blown sand; Crushed-rock embankment; active cooling effect; the Qinghai-Tibet Railway