摘要
常用尼龙阻沙网的孔隙度为均匀分布,而风沙流结构在垂直方向上是非均匀分布的。通过设计4种孔隙度非均匀分布的尼龙阻沙网:大条带上疏下密式(A)、大条带上密下疏式(B)、小条带疏密相间式(C),将其布设在塔克拉玛干沙漠腹地的垄间平地,以均匀结构阻沙网为对照(CK)。对4种阻沙网前后的风速变化、防风效能、积沙形态、积沙量进行对比。结果表明:①B阻沙网有效防护距离最短,仅为6H(H为阻沙网的高度),其余3种结构有效防护距离差别不大,均为15H;在网后10H处0.15 m、0.3 m和0.5 m 3个观测高度,风速削弱程度的平均值存在明显差异,呈C>A>B>CK。②在风季后期,4种结构阻沙网前后积沙量B最小,其余3种类型差别不大。③综合考虑防风和阻沙效益,C阻沙网提供了一个较好的结构模式,防护效益最好,B阻沙网最差,A和CK阻沙网效益相差不大。研究结果为高立式沙障结构优化设计提供了参考依据。
Sand blocking nylon nets are commonly knitted with uniform porosity, however, vertical sand flux was unevenly distributed. In this study, three types of sand blocking nylon nets with different structure were designed, i. e. , the wide tripped net with sparse upper-porosity and dense lower-porosity （A）, wide tripped net with dense upper-porosity and sparse lower-porosity （B） , and narrow tripped net with alternative dense and sparse porosity （C）. They were settled on the inter-dune sand lowland in the hinterland of the Taklimakan Desert, and the net with uniform porosity was taken as the contrast （CK）. The wind speed at different heights from ground surface and the deflation depth and deposition height on the ground around the nets were surveyed. The collected data were an alyzed to understand the wind prevention and sand control effect of the nets. The results are as follows ： The ef fective wind prevention range of the three types of nets （A, C and CK） was about 15H, but that of net B was about 6H only. The wind speed reduction rates at 3 heights （0.15 m, 0.3 m and 0. 5 m） from IOH range were signifi cantly different, and they were in an order of C 〉 A 〉 B 〉 CK; The difference of deposited sand mass of the three types of nets （A, C and CK） was not so significant, but the deposited sand mass of net type B was lower than that of other three types of nets ： In conclusion, the wind prevention and sand control effect of net type C was the highest, that of net type B was the lowest, and there was no significant difference between net type A and CK. These results could provide a new idea for the optimal design of the structure of high sand barriers, and give some scientific basis for sand control engineering construction.
出处
《干旱区研究》
CSCD
北大核心
2014年第2期369-374,共6页
Arid Zone Research
基金
新疆维吾尔自治区重大科技专项课题(201130106-3)
新疆维吾尔自治区科技支疆项目(201291106)
中国科学院知识创新工程青年方向项目(KZCX2-YW-QN316)
国家自然科学基金(41201016)
关键词
尼龙阻沙网
风速变化
防风效能
积沙形态
积沙量
塔克拉玛干
sand blocking nylon net
wind speed reduction
wind prevention efficiency
morphological feature ofsand deposition
deposited sand mass
Taklimakan
