兰新线即有土堤式挡风墙的改造形式对背风侧流场的影响

为了研究兰新线即有土堤式挡风墙的挡风性能,寻找即有土堤式挡风墙不能满足列车安全运行的原因及解决方法,本文应用数值模拟以及分析实测数据的方法得到即有土堤式挡风墙背风侧的流场特性,并为即有土堤式挡风墙的改造提出2种方案,分析对比3种优化改造后土堤式挡风墙在不同风速下背风侧的特征线风速、流场结构、大风遮蔽效应系数。结果表明:即有土堤式挡风墙背风侧无明显涡流区,挡风性能不满足列车安全运行的要求,相对于即有土堤式挡风墙,改造后土堤式挡风墙在不同风速下左侧加高、中部加高、右侧加高土堤式挡风墙挡风性能差异小,但挡风性能均有明显提高,均能满足列车安全运行的要求。优化改造后的土堤式挡风墙为将来类似防风沙工程优化设计提供参考和依据。

Impact of the Transformation in the Form of Existing Earth Embankment Wind-break Wall of Lanxin Railway on the Leeward Side Flow Field

In order to research the wind-breake performance of existing wind-break wall in lanxin railway and find reasons which can′t meets requirements of train running.Numerical simulation and the analysis of the measured data are used in this paper to get the results of the flow field characteristics on leeward side.Two schemes to upgrade the existing earth embankment wind-break wall are presented,and the wind speed of characteristic line,flow field structure,and the the coefficient of shadowing effect of three heightening types of them are compared.The results showd that there is no obvious eddy zone on the leeward side flow field of existing earth embankment wind-break wall.So it can′t meets requirements of running.Compared to existing earth embankment wind-break wall in different wind speed,The differences of wind-breake performance on the left heightened and right heightened is small.But improved enormously than existing one.So it can meets the requirements of running.The optimized earth embankment wind-break wall can provide references and basis to other similar engineering.