新亚欧大陆桥新疆段风沙流活动特性及停积规律

Characteristics of activity and sediment of wind-sand current in Xinjiang line of New Eurasian Continental Bridge

通过对新亚欧大陆桥新疆段不同区段风沙流实测资料的分析，探讨了砾漠区和沙漠区的风沙流活动特 性及其停积规律．研究表明，风沙流随风力条件、下垫面状况而变化，其搬运能力与风力大小呈正相关；高 程与含沙量（％）对数尺度之间具有良好的线性关系，含沙量随高度增加成指数规律衰减；砾漠区沙粒粗大， 在２．０ｍ 以下高程其含量随高度增大而明显增大，沙漠区风沙流物质成分以细粒为主（占７１％）；物质运动以 跃移为主，易在低路堤边坡，半填、半挖路基和浅路堑处沉降积沙；在风沙流运动方向与线路走向的夹角 ＜３０°时，积沙厚度较小，而当其＞４５°时，积沙量随夹角增大呈明显增多的趋势．

Based on and analysis of field investigation data of wind-sand current in different sections of Xinjiang line, New Eurasian Continental Bridge, the characteristics of wind-sand current activity and it s sediment in both gobi and desert areas were studied in the paper. The results are as follows: (1) The characteristics of wind-sand current vary with the condition of wind and the material on the ground, and the transportation ability of wind-sand current is related to the degree of wind with positive correlation. (2)The sand content in gobi area concentrated mainly below 2 meters elevation in gobi area, ac- counting for 95.9% of the total and below 40 cm elevation in desert area, accounting for 99%. (3) In desert area, more than seventy-percent material of wind-sand current is fine sand. Comparing with desert area, the size of sand in gobi area is much bigger. The content of crude sand and gravel are much more than that of fine sand, and it increases obviously as the height increasing within 2 meters elevation in gobi area. (4)The sediment of wind-sand current is related to embankment. The depth of accumulated sand is small as the included angle between wind-sand current and the direction of railway is below 30°while the content of accumulated sand increases obviously with the included angle as the angle is over 45°