中文摘要：

青藏铁路地处高寒低压环境，地表风沙危害形成过程与干旱、半干旱沙漠和戈壁地区有较大差异。青藏铁路沿线多大风、风力强劲、风向相对单一，主导风向以西风为主；各站点年输沙势DP均高于400VU，属于高风能环境，合成输沙方向间于85．8°～89．8°；“风旱同季”，风水复合侵蚀和冻融作用时空交错，地表抗蚀能力差，从而加剧了铁路沿线风沙活动强度。通过对青藏铁路沿线风沙灾害特点、风动力环境、工程防沙措施及其防护机理等分析，提出了青藏铁路沿线风沙危害防治原则和防护体系：应逐步建立以阻沙栅栏、砾石方格、化学固沙、植被恢复相结合的综合防治体系。

英文摘要：

The Qinghai-Tibet Railway, the longest high-altitude railway in the world, is frequently damaged by windblown sand because of strong winds and abundant sand. On the basis of meteorological data, in situ observations and wind tunnel experiments, this paper aims to clarify the characteristics of windblown sand, and to show the dy- namical environment of sand activities. According to climate data, the windy period combines with an arid seasonal climate to increase the risk of blowing sand in this area. Wind-blown sand presents unidirectional characteristics and its prevailing direction is westerly. The annual drift potential along the Qinghai-Tibet Railway reaches more than 400 VU, which belongs to a high-energy wind environment. The resultant drift potential ranges from 85.8° to 89.8°, which indicates that westerly sand-laden wind prevails in this region. It rarely snows in winter and the earth＇ s surface is usually bare. Meanwhile, winter is also the windy season with the peak wind speed of 38 m/s. It can be eas- ily found that the windy period always accompanies with a drought season. The dominant directions of sand transport are westerly in the observed period. Sand transport per unit width （cm） from a westerly direction is 55.7 kg in spring in the Cuonahu region, which indicates strong activity of wind-blown sand. The corrosion resistance on earth is very bad because of the multi-agents actions, such as water, wind and freeze-thaw roles. Sand-damage control along the Qinghai-Tibet Railway should adopt an integrated protection system, not a single sand-control measure. The results of the research have three implications for the design of future sand-control structures. Firstly, sand-control mea- sures must be designed to decrease wind velocity sufficiently and protect natural vegetation along the Qinghai-Tibet Railway, so that abundant sands could be blocked away from the railway. Secondly, results show that sand-driving wind presents a unidirectional flow along the Qinghai-Tibet Railway, so sand control