摘要
应用Fluent软件对风沙地区铁路沿线挡沙堤周围气流运动特性进行数值模拟,探讨挡沙堤风沙防护效果的关键影响因素。研究结果表明:挡沙堤周围气流在迎风坡、堤顶和背风坡分别形成减速区、高速区和紊流区;挡沙堤越高,坡度越大,迎风坡坡脚风速衰减幅度越大,背风侧回流风速峰值和回流区长度越大,防沙效果越好;综合考虑防护效果和工程造价,建议挡沙堤的布设高度宜取为1.5~2.0 m,坡率宜取为1∶1.5;截沙沟、挡沙堤组合式防沙工程,宜将截沙沟设置在上风向。提出了一种新型的挡沙堤顶部加设中立式高密度聚乙烯网沙障的复合式挡沙堤,与传统挡沙堤相比,其性能优,而工程造价大幅降低。建议防沙设计中优先采用新型挡沙堤。
The motion characteristics of airflow around the sand retaining dike in sandy area along railway line were simulated by using Fluent software and the key factors of sand retaining dike influencing sand protection effect were discussed.Results show that airflow around the sand retaining dike forms the deceleration area at windward slope,the high speed area at levee crown and the turbulent area at leeward slope,the higher the height and slope of sand retaining dike are,the greater the attenuation amplitude of air velocity at toe of windward slope,the counter-flow velocity peak and counter-flow zone length at leeward slope will be,which achieves better effect of sand protection,the height of the sand retaining dike is recommended as1.5?2.0m and the slope ratio is recommended as1:1.5based on comprehensive consideration of protection effect and the project cost,the sand intercepting ditch should be set up at the upwind direction in the combined sand protection project of sand intercepting ditch and sand retaining dike,and a new kind of composite sand retaining dike is put forward with the neutral type high-density polyethylene(HDPE)net sand-protecting barrier installed at the top of sand retaining dike,which has excellent performance and the low construction cost compared with the traditional sand retaining dike.It is recommended that this new type of sand retaining dike should be adopted in sand protection design with priority.
作者
石龙
李凯崇
蒋富强
薛春晓
孔令伟
SHI Long;LI Kaichong;JIANG Fuqiang;XUE Chunxiao;KONG Lingwei(Northwest Research Institute Co.,Ltd of C. R. E. C.,Lanzhou Gansu 730000,China)
出处
《铁道建筑》
北大核心
2017年第9期119-123,共5页
Railway Engineering
基金
中国中铁股份有限公司科技开发计划(2015-KJ035-G004-03)
科技部科研院所技术开发研究专项资金项目(2013EG123034)
关键词
铁路路基
风沙地区
挡沙堤
截沙沟
流场
设计参数优化
数值分析
防护效果
Railway subgrade
Sandy area
Sand retaining dike
Flow field
Sand intercepting ditch
Design parameters optimization
Numerical analysis
Protection effect
