风雪流对铁路路堤的响应规律数值模拟分析  

Numerical Simulation Analysis of the Response Law of Wind-snow Flow to Railway Embankment

作　　者：李舟 薛春晓 石龙 LI Zhou;XUE Chunxiao;SHI Long(Northwest Research Institute Co.,Ltd.of CREC,Lanzhou 730000,China;School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]中铁西北科学研究院有限公司,兰州730000 [2]西南交通大学土木工程学院,成都610031

出　　处：《铁道标准设计》2021年第9期34-39,共6页Railway Standard Design

基　　金：国家科技部科研院所专项资金(2014EC123035)。

摘　　要：受全球极端气候影响,北方地区冬季风吹雪灾害频发,严重威胁铁路的安全运行。为减轻冬季风吹雪地区铁路雪阻现象带来的安全隐患,基于计算流体力学软件中的欧拉双流体非稳态模型,对路堤周围的风雪流运动特征进行数值模拟,并分析路堤断面设计参数对其雪阻效应的影响。研究结果表明:气流受路堤扰动后速度重新分布,分别在迎风坡和背风坡形成气流减速区和紊流区,在路堤顶面气流分成两层,贴近地表的下层气流速度大幅度降低,形成弱风区,上层气流速度得到加强,形成强风区;风速较低的坡脚是路堤积雪主要区域,与平坦地形相比,上坡风路堤周围风速较大,积雪概率降低,下坡风路堤周围风速较小,积雪概率增大;风雪流盛行地区,为减小风吹雪危害,路堤高度不宜大于5 m,边坡坡度不宜陡于1∶1.75;路堤位于下坡风时最易形成路面雪阻,平坦地形次之,上坡风最不易形成路面雪阻;选线时宜将铁路布置在上坡风位置通过,风吹雪严重地区,避免将铁路布置在下坡风处。Frequent snowdrift disasters in winter of the northern region affected by the global extreme climate seriously threaten the safe operation of railways.To alleviate the hidden safety hazard caused by snow blockage of railway in winter,the motion characteristics of wind-snow flow around the embankment are numerically simulated based on Euler twofluid unsteady state model in computational fluid dynamics software,and the influence of the embankment section design parameters on snow blockage effect is analyzed.The results show that the velocity of the airflow is redistributed after being disturbed by the embankment,forming an airflow deceleration zone on the windward slope and a turbulence zone on the leeward slope respectively.The airflow is divided into two layers on the top of the embankment.The airflow velocity of the lower layer close to the embankment surface is greatly reduced,forming a weak wind area;while the airflow velocity of the upper layer is strengthened,forming a strong wind area.The main accumulated snow areas of the embankment are mainly located at the foot of the slope owing to low wind speed.Compared with flat terrain,the probability of snow accumulation around the windward embankment is lower due to relatively high wind velocity;while it is higher around the leeward embankment due to relatively low wind velocity.To reduce the snowdrift hazards in these areas with prevailing wind-snow flow,the height of the embankment should not be greater than 5 m,and the slope of the embankment should not be steeper than 1∶1.75.The snow blockage on the railway surface is most likely to occur in the leeward embankment,followed by flat terrain,and it is most unlikely to cause snow blockage in windward embankment.In route selection,the railway line should be located with up-slope wind.In heavy snowdrift area,the railway line should not be located with down-slope wind.

关 键 词：风雪流 铁路路堤 流场结构 雪阻效应 响应规律 数值模拟 

分 类 号：U213.11[交通运输工程—道路与铁道工程]