新疆单线铁路土堤式挡风墙坡角优化研究

Optimization Research on the Slope Angle of the Earth Type Windbreak Wall of Xinjiang Single-Track Railway

为提高新疆单线铁路土堤式挡风墙的防风效果,防止列车倾覆,提出只改变挡风墙的迎风侧坡角而背风侧坡角不变(方案1),以及挡风墙的迎风侧坡角和背风侧坡角相等且同步改变(方案2)的2种优化方案。采用数值模拟计算方法对比这2种优化方案对列车气动力系数的影响。结果表明:在列车处于静止状态下,方案1中挡风墙迎风侧最佳坡角为57°,方案2中挡风墙迎风侧和背风侧最佳坡角均为69°;在列车以20～120km.h-1速度运行的动态状态下,按方案1,为达到列车倾覆力矩为0的最佳防风效果,挡风墙迎风侧坡角也必须随着列车运行速度的增大而增大;而按方案2,挡风墙的迎风侧和背风侧坡角基本不随列车速度的变化而变化。因此建议在实际工程中采用方案2进行土堤式挡风墙坡脚的优化设计。

In order to improve the windbreak effect of the earth type windbreak wall of Xinjiang single-track railway and to prevent trains from overturning, two optimization schemes were proposed. Scheme 1 was to change only the windward slope angle, while scheme 2 was to change synchronously both the windward and leeward slope angles which were equal. Numerical simulation method was used to analyze and compare the influence of two optimization schemes on the aerodynamic coefficient of train. Results show that when the train is under stationary state, the optimum windward slope angle is 57° in project 1, while both the windward and leeward slope angles are 69° in project 2. Under the dynamic condition that when the train is running at the speed of 20~120 km&middoth-1, in order to achieve the best windbreak effect with the overturning moment of train is 0, the windward slope angle must also increase with the increase of train speed in scheme 1. But in scheme 2, both the windward and leeward slope angles are nearly unchanged with train speed. Thus, scheme 2 is proposed to be adopted for the optimization design of earth type windbreak wall in practical engineering.