KMS XINJIANG INSTITUTE OF ECOLOGY AND GEOGRAPHY，CAS
| 公路护栏风沙效应的风洞模拟 | |
| 袁鑫鑫 | |
| Subtype | 硕士 |
| Thesis Advisor | 雷加强 |
| 2016 | |
| Degree Grantor | 中国科学院大学 |
| Place of Conferral | 北京 |
| Degree Discipline | 水土保持与荒漠化防治 |
| Keyword | 公路 护栏 风沙效应 风洞模拟 |
| Abstract | 风沙活动区公路路面积沙严重影响行车安全，而道路护栏则是导致路面积沙的重要原因，为查明不同类型公路护栏对路面积沙的影响，通过室内风洞开展了混凝土(A型)护栏、波形（B型）护栏，缆索（C型）护栏在8m·s-1、10m·s-1、12m·s-1净风和8 m·s-1挟沙风下的模拟试验。通过对不同类型护栏的风场、平均防风效能、积沙状况的对比分析，主要研究结果如下： （1）风场结果表明A型护栏下部不存在加速区，B、C型则分别存在较小和较大的加速区。加速区的存在会导致风沙流不饱和，加速区越大，护栏下部越不易形成积沙。因此C型护栏下部路面最不易形成积沙，B型次之，A型较易形成积沙；A、B、C型护栏风影区范围依次减小，风影区内风速迅速降低导致风沙流过饱和而出现积沙，因此风影区范围越大，越容易形成大面积积沙。因此相同风速下A、B、C型护栏路面的积沙面积应依次减小；A、B、C型护栏风影区中心位置依次升高，由于风沙流含沙量随高度升高而降低，因此风影区位置越低，受风速降低而造成的积沙量越大。因此，A、B、C型护栏路面的积沙量应依次减小。 （2）防风效能结果表明A型护栏不同高度处防风效能总体相对较大，C型较小，B介于前两者之间； A、B、C型护栏的平均防风效能依次大幅降低。A、B、C型护栏对风的削弱依次大幅降低，因此由A、B、C型护栏的扰动而导致的路面积沙危害应依次大幅降低。 （3）积沙状况结果表明A型护栏下风向积沙较多，B型相对较少，C型基本无积沙，该结果说明沙区公路安装A型护栏在护栏附近较易形成路面积沙而严重影响行车安全，B型护栏的影响相对A型较小，C型基本不会产生积沙而影响行车安全。 因此，不同类型护栏的风场、平均防风效能、积沙状况试验结果一致表明不同类型护栏扰动下风沙活动区域公路路面产生积沙危害的程度明显不同，安装混凝土（A型）护栏的路面较易积沙且积沙面积较大，缆索（C型）护栏几乎不会造成路面积沙，波形（B型）护栏介于二者之间。因此建议风沙活动区域公路建设中选用缆索护栏以避免路面形成积沙而影响行车安全。 |
| Other Abstract | Aeolian sand on road in sand drifting aeras seriously affect driving safety.To reveal the effects of different kinds of guardrails in sand drifting areas， concrete guardrail(type A)， waveform guardrail(type B)， cable type barrier(C) wind tunnel simulation were conducted under the net wind velocity of 8m/s，10 m/s， 12 m/s.By comparison of the wind field of different barrier， the condition of average wind efficiency and aeolian sand status， the results consistently show that: (1)Wind field results show that the lower part of type A guardrail has no acceleration area，but type B and Crespectively hasa smaller and a lager acceleration area. The existence of accelerate area leads to unsaturated sand flow，the accelerate area lager， the greater the fence bottom is not easy to form serious sand deposition.So C type guardrail pavement is the most difficult to form sand deposition， type B， type A is easy to form sand deposition;Wind shadow zone of type A， B， C guardrailgradually decreases， and in turn the wind shadow area wind speed reduced quickly lead to sand flow saturation and appear sand deposition， therefore the greater the wind shadow area， the easier it is to form large area sand deposition.Therefore under the same wind speed， type A， B， C the sand deposition road area should decrease in turn;A， B， C type guardrail， in turn， increases the wind shadow center position， due to sand flow sediment concentration increases with height is reduced， so the wind shadow position is lower， the sediment deposition caused by wind speed reduced.As A result， A， B， C type guardrail sediment deposition onpavement should be reduced in turn. (2)Type A guardrail height difference windproof efficiency overall is opposite bigger， C is very small， B between the A and C; Average wind efficiency of A， B， C type guardrail greatly reduced in turn.Type A， B， C， the weakening of the barrier to the wind， in turn， greatly reduced， sothe road area of sand deposition of A， B， C type guardrail caused by disturbance and sand hazard should be greatly reduced in turn. (3)Sand deposition results showing that the sand depositionof type A guardrail in downwindis large， B is relatively small，basically C has no sand deposition.The results show that the sand area highway installed type A guardrail formingsand deposition more easily on road area andmaking serious influence on driving safety，the influence of B type guardrail is relatively small， the influence of C type basically won't produce anysand depositionand won't affect driving safety. By comparison of the wind field of different barrier， the condition of average wind efficiency and aeolian sand status， the results consistently show that:sand hazards on highway pavement under different types of guardrail are significantly different，pavement with(type A) concrete barriers has the greatest accumulating sand amount and the sand accumulating area is the largest， cable (type C) fence almost won't cause sand accumulating on pavement， waveform (type B) barrier performs mediocre.Therefore we suggest to choose cable guardrail in highway construction in order to avoid the sand accumulating on pavement in sand drifting regions. |
| Subject Area | 水土保持与荒漠化防治 |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | http://ir.xjlas.org/handle/365004/14702 |
| Collection | 研究系统_荒漠环境研究室 |
| Affiliation | 中科院新疆生态与地理研究所 |
| Recommended Citation GB/T 7714 | 袁鑫鑫. 公路护栏风沙效应的风洞模拟[D]. 北京. 中国科学院大学,2016. |
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