青藏铁路沿线阻沙栅栏防护机理及其效应分析

摘要/Abstract

摘要： 对青藏铁路沿线阻沙栅栏的流场结构、阻沙效率进行风洞模拟实验,对沱沱河路段阻沙栅栏的野外积沙形态进行观测。结果显示,气流经过栅栏时有遇阻抬升、集流加速、减速沉降区和消散恢复区。在越过栅栏后形成两个减速恢复区和两个加速区,减速区分别距地表3 cm和20 cm处,加速区分别位于近地表和35 cm高度处。随来流风速的增加,栅栏前加速区起始范围向栅栏逼近,而栅栏后恢复区起点向远离栅栏方向发展。当气流越过栅栏后风速急剧降低,导致沙粒减速沉降。随进口风速的增加,栅栏间阻沙量和越过栅栏后输出沙量呈指数关系递增。铁路沿线采用的栅栏阻沙效率达80%以上,且随风速的增加呈线性关系递减。沱沱河路段阻沙栅栏西南侧以风蚀为主,最大风蚀深度达16\^7 cm,其余区域表现为积沙,最大积沙厚度达19\^9 cm。

关键词: 青藏铁路, 阻沙栅栏, 流场结构, 防护机理

Abstract: The flow fields, protective efficiency of sand-blocking fences are simulated in wind tunnel experiment, and the erosion or accumulation phenomena of fences along the Qinghai-Tibet Railway in the section of Tuotuohe River region are observed in situ. There exists blocked-rising, collected-accelerating, decreased-depositing and diffused-restoring regions when airflow traverses sand-blocking fences. Two decreased-restoring regions as well as two accelerating regions present behind the fences. The decreased-restoring regions happen at the height of 3 cm and 20 cm above the earth surface, and the two accelerating regions happen within near surface and at the height of 35 cm above the earth surface, respectively. As the inlet wind speed increases, the wind accelerating range before fences approaches the fences and the starting point of wind-restoring region departs away fences. Wind speed abruptly decreases just after fences, which leads sand grains to deposit in this region. Sand-blocking mass and sand transport after fences increase exponentially with wind speed. Fence exerts distinct effect with sand-blocking ratio of over 80% along Qinghai-Tibet Railway. Sand-blocking ratio decreases linearly with wind speed. Wind erosion occurs on the southwest area of sand-blocking fence in the section of Tuotuohe River region, with the most wind-erosion depth of 16\^7 cm, and it represents sand burial over the other areas and the most sand-accumulation depth is 19\^9 cm.

Key words: Qinghai-Tibet Railway, sand-blocking fence, structure of flow field, protective mechanism

中图分类号:

U216.41

张克存;屈建军;牛清河;姚正毅;韩庆杰. 青藏铁路沿线阻沙栅栏防护机理及其效应分析[J]. 中国沙漠, 2011, 31(1): 16-20.

ZHANG Ke-cun;QU Jian-jun;NIU Qing-he;YAO Zheng-yi;HAN Qing-jie. Protective Mechanism and Efficiency of Sand-blocking Fences along Qinghai-Tibet Railway[J]. JOURNAL OF DESERT RESEARCH, 2011, 31(1): 16-20.

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