排序方式： 共有6条查询结果，搜索用时 46 毫秒
1
1.
新疆S214（考干-米兰，考米线）公路位于库鲁克塔格沙漠东南缘，穿越台特玛湖干涸湖盆。由于该区气候干旱，风力强劲，沙源丰富，流动沙丘广布且快速移动，风沙危害对公路运输构成严重威胁。通过对风沙环境和风沙危害定位观测和土壤水盐特征系统调查，确定了风沙危害极为严重的公路区段，提出了合理的风沙防护措施及防沙体系结构。结果表明：该区具有明显的单风向风况，主要盛行ENE和NE风，偶有反向风沙活动，起沙风频率、输沙势、输沙率极高，属于高能-大比率风能环境；受土壤水分、盐分含量影响，地表紧实度差异较大，部分地段为极疏松的沙层，部分地段为紧实的盐壳；S214公路风沙危害防护区段为K4+900~K18+200，设计建造的阻-固-输相结合的机械-植物复合防沙体系，防沙效果明显，保障了道路安全运营。这一强风沙、高盐区公路防沙体系建设模式可为类似环境地区工程防沙提供借鉴。 相似文献
2.
对新疆S214省道台特玛湖干涸湖盆段防沙体系内外的风沙流输沙和风速进行了同步观测,数据分析表明：观测时防沙体系中阻固沙带已拦截了大量风沙,虽近地表风速被削弱程度不大,但风沙流输沙的43.26%仍可被防沙体系所拦截和固定,而剩余部分则可借助路侧输沙带的较大风力输移到公路下风侧,且不产生路面沙害,表明阻-固-输结合型防沙体系非常适宜单风向强风沙环境。S214省道防沙实践可为其他强风沙环境公路防沙提供重要借鉴经验。 相似文献
3.
不同发育阶段新月形沙丘表面粒度特征 总被引：1，自引：0，他引：1
以塔克拉玛干沙漠腹地垄间平地新月形沙丘的4个发育阶段(饼状沙丘(PD)、盾状沙丘(SD)、雏形新月形沙丘(PCD)、新月形沙丘(TCD))为研究对象,对沙丘表面不同地貌部位的沙物质取样并进行粒度分析,以期发现新月形沙丘不同发育阶段表面粒度的变化规律,结果表明:4种沙丘丘顶或临近丘顶处细砂及极细砂含量最小、粒径最粗、分选性最差,向两侧细砂及极细砂含量逐渐增大、粒径逐渐变细、分选逐渐变好。各发育阶段之间沙粒级配、平均粒径、分选系数的变化规律则需区分不同地貌部位。在迎风坡这3者没有较大差异;在背风坡,细砂及极细砂含量、平均粒径、分选系数均随着沙丘的发育而增大。另外,峰度和偏度并不随着新月形沙丘的发育有明显的变化,均属于近对称中等峰态且为单峰。 相似文献
4.
There is a severe phenomenon of blowing snow by wind in winter in Mayitas area of Xinjiang. Road traffic interruptions and casualties caused by wind and snow disasters often occur. The existing engineering measures can alleviate the problems of low visibility and problems with accumulating snow on pavement caused by wind and snow to a certain extent, but cannot completely eliminate the impact. Aiming at the problem that the blowing snow disaster difficult to be completely cured under strong wind conditions, a shed tunnel engineering treatment scheme is proposed, and a wind tunnel simulation experiment is carried out on the shed tunnel form and snow prevention scheme at the entrance of the tunnel. The wind tunnel experimental section is 8 m long, 1. 3 m horizontally wide and 1 m high. The shed tunnel model is made by 1:60 scale 3D printing method, the snow barrier model is made of wooden strips, and the simulation medium is made of fine sand, refined salt and sawdust. Firstly, three kinds of shed structures, including fully enclosed, overhanging and ventilated, were simulated under the condition of 90° wind direction, and compared with the form of blowing snow stacking. Three parameters for similarity were used:density, particle size and stacking shape. The similarity is determined by weighted Euclidean distance between simulation medium and blowing snow, the similarity of the slump angle of the predecessors is verified, and the most suitable medium for simulating blowing snow is deduced. According to the experimental results, combined with the actual situation of wind blowing and snow disasters in Mayitas, flow field of the closed shed tunnel by a wind direction angle of 30° has been separately conducted with or without protective measures. The results show that when the wind tunnel stacking experiment is used to study the deposition state of blowing snow under non-low temperature conditions, the sawdust has good similarity with the blowing snow in the process of wind and snow movement. A large amount of medium was poured into the ventilated shed during the experiment, which proved that its anti-wind and snow performance was not ideal. By contrast, the closed shed and the overhanging shed have better wind and snow prevention effects. The snow barrier has a good blowing snow inhibition function at the entrance. From the stacking experiment, in the comparison with and without snow barrier, volume of the medium in the shed is very different, which proves that the snow barrier can effectively prevent the blowing snow from entering the shed. Among them, the difference in wind speed inside and outside the shed is obvious, which proves that snow barrier can significantly reduce the wind speed outside the shed and has the function of inhibiting the formation of weak wind areas inside the shed. The study has confirmed that the shed tunnel project with suitable snow barrier layout plan for tunnel entrance protection is an effective means to control wind and snow disasters. For highway traffic in Xinjiang, it is a feasible solution to use shed tunnel engineering to control blowing snow disasters. After dealing with the snow deposition at the entrance of shed tunnel, the shed tunnel engineering form of low-cost environment integration and the vehicle operation safety guarantee measures of long-distance shed tunnel are the problems that need to be solved in the future. © 2022 Tianjin Press of Chinese Herbal Medicines. All rights reserved. 相似文献
5.
台特玛湖干涸湖盆区植物风影沙丘的形态特征 总被引：1，自引：0，他引：1
对台特玛湖干涸湖盆区盐穗木、柽柳和碱蓬3种植物风影沙丘的形态参数进行野外了测定,应用统计学方法,分析对比了不同植物风影沙丘的形态特征及阻沙能力。结果表明：（1）风影沙丘处于由沙嘴向沙堆演化阶段,沙丘形态参数间相关性显著（P<0.01）,其中沙丘高度与水平尺度相关性较好,沙丘垂向发育速度快于水平扩展。（2）风影沙丘与植物形态参数间亦存在相关性,受植物生物特性的影响,不同植物的相关性差异较大,其中碱蓬呈高度正相关（R>0.85,沙丘背风坡坡度除外）,盐穗木次之,柽柳灌丛相关性微弱。（3）在相同的区域环境下,3种植物的单株阻沙能力呈柽柳 > 盐穗木 > 碱蓬,盐穗木、碱蓬积沙量受株高影响较大,两者呈二次函数关系;柽柳积沙量主要取决于灌丛迎风剖面的面积。 相似文献
6.
塔克拉玛干沙漠腹地沙粒胶结体的粒度特征 总被引：1，自引：1，他引：0
对塔克拉玛干沙漠腹地沙粒胶结体进行溶蚀分散获取组成沙粒,采用激光粒度仪分析粒度成分,并与区域内沙丘沙、垄间平地沙和风沙流输沙的粒度特征进行对比,分析沙粒胶结体的粒度特征。结果表明：（1）沙粒胶结体中沙粒粒径呈多峰态分布,垄间平地沙呈双峰态分布,而沙丘沙和风沙流输沙呈单峰态分布;（2）沙粒胶结体内沙粒分选性较差,偏度属正偏,平均粒径（3.17 Φ）介于沙丘沙（3.10 Φ）和垄间地沙（3.28 Φ）、风沙流输沙（3.67 Φ）之间;（3）沙粒胶结体中沙物质主要组分为细沙和极细沙,与沙丘沙、垄间平沙地沙一致,而与风沙流输沙（极细沙和粉沙）不一致。与沙丘沙、垄间平地沙以及风沙流输沙相比,沙粒胶结体中粉沙、黏土和中沙相对富集,是现代地表物质的混合物;（4）与沙丘沙、垄间平地沙和风沙流输沙相比,沙粒胶结体内沙粒的蠕移-跃移、跃移-悬移截点粒径均偏细,蠕移组分所占比重很高。从组成颗粒的粒度组成来看,沙粒胶结体的形成受局地沙源和风动力的共同影响,是特殊环境条件下现代地表过程的产物。 相似文献
1