| 青藏铁路沱沱河路段流场特征及沙害形成机理 |
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| 引用本文： | 张克存,牛清河,屈建军,韩庆杰.青藏铁路沱沱河路段流场特征及沙害形成机理[J].干旱区研究,2010,27(2). |
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| 作者姓名： | 张克存 牛清河 屈建军 韩庆杰 |
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| 作者单位： | 1. 中国科学院寒区旱区环境与工程研究所敦煌戈壁荒漠生态与环境研究站,甘肃,敦煌,736200;中国科学院寒区旱区环境与工程研究所沙漠与沙漠化重点实验室,甘肃,兰州,730000
2. 中国科学院寒区旱区环境与工程研究所敦煌戈壁荒漠生态与环境研究站,甘肃,敦煌,736200 |
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| 摘 要： | 通过对青藏铁路沱沱河路段路基流场结构、风速廓线特征的风洞模拟实验研究,发现气流在途经铁路路基时,路基断面对近地表流场改变极大,在其两侧形成明显的遇阻抬升区、集流加速区、减速沉降区以及消散恢复区。铁路沙害的形成主要是路基迎风侧气流由于遇阻抬升和集流加速,对路肩和路基中上部产生风蚀;随着气流加速抬升,底层砂粒以跌落沉降的方式堆积在路基迎风坡坡脚,造成路基沙埋;当气流越过路基,在背风侧由于减速沉降和涡旋运动,风沙流处于过饱和状态,将所携带的大量砂粒堆积在背风坡。
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| 关 键 词： | 沱沱河 流场特征 风沙危害 机理 青藏铁路 |
Study on the Characteristics of Flow Field and the Mechanism of Wind-blown Sand Disasters in the Tuotuohe Region along the Qinghai-Tibet Railway |
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| ZHANG Ke-cun,NIU Qing-he,QU Jian-jun,HAN Qing-jie.Study on the Characteristics of Flow Field and the Mechanism of Wind-blown Sand Disasters in the Tuotuohe Region along the Qinghai-Tibet Railway[J].Arid Zone Research,2010,27(2). |
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| Authors: | ZHANG Ke-cun NIU Qing-he QU Jian-jun HAN Qing-jie |
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| Abstract: | Qinghai-Tibet Railway,with an average altitude of 4 500 m a. s. l. ,is the longest railway in the high-ahitude region in the world. It passes through 550 km-long permafrost belt and crosses the Kunlun Mountains and Tanggulha Mountains on the Qinghai-Tibetan Plateau. Based on the wind tunnel experiment of flow filed structure and wind profiles around the railway bed along the Tuotuohe section of the Qinghai-Tibet Railway,it is considered that a section of railway bed will obviously change the pattern of flow field near ground surface,and there are the obvious blocked-rising area,collected-accelerating area,decreased-depositing area and diffused-restoring area of airflow in a flow field. The mechanism of wind-blown sand disaster formation along the railway is mainly as follows: wind erosion occurs at the railway shoulder or the mid-upper part of railway bed because airflow at windward slope is forced to lift and accelerate ; sand grains in the bottom layer deposit at the toe of windward section and bury the railway bed as airflow is enforced to lift; wind-blown sand is in a supersaturation state and accumulates at leeward slope of the railway bed because of the wind speed decrease and eddy motion when airflow gets across the railway bed. The Qinghai-Tibet Railway is destined to suffer from wind-blown sand disasters. With climate change and increase of human activities,the occurring frequency of wind-blown sand disasters along the railway will increase in the future. In a word,it has become a new challenge for both government and scientists how to control wind-blown sand disasters along the Qinghai-Tibet Railway in an effective and scientific way. |
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| Keywords: | Tuotuohe section flow field mechanism of wind-blown sand disaster Qinghai-Tibet Railway |
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