铁路路堤周围的风沙分布特征及堆积过程

Distribution Characteristics and Accumulation Process of Sands around Railway Embankment

风沙地区的铁路面临风蚀和沙埋两种危害,严重影响着线路的正常运行.基于欧拉两相流模型,建立了铁路路堤风沙流运动的三维数值模型,分析了路堤周围的风沙流分布特征,研究了沙粒的堆积过程.结果表明:路堤周围流场速度分布沿着风速方向变大,且在迎风坡坡肩处最大值增加了25%;沙粒在铁路路堤堆积的过程可分为路堤坡面积沙阶段、路堤顶面积沙阶段、路堤坡面积沙滑落阶段、路堤坡脚积沙阶段;风沙流速度提高时,路堤顶端最大积沙体积分数增加且积沙区域增大.

Based on Euler two-phase model, a three-dimensional numerical model of sand flow moving over railway embankment was established. The sand-flow distribution characteristics were analyzed, and the accumulation process of sand grains was explored. The results show that the sand-flow velocity distribution around the embankment is increased along the wind direction, and the maximum velocity in the windward slope shoulder is increased by 25 %. The accumulation process of sand grains on the railway embankment can be divided into embankment slope sand accumulation stage, embankment top surface sand accumulation stage, embankment slope sand slide stage and embankment toe sand accumulation stage. It also indicates that the maximum sand volume fraction increases on the embankment top surface, and sands accumulating area also increases with the wind-sand flow speed increasing.