路基边坡坡面冲刷强度探讨

Study on Scouring Intensity of Subgrade Slope

在南方花岗岩地区和北方黄土地区修建铁路公路时 ,路基边坡常常会发生较为严重的坡面冲刷问题。坡面冲刷强度是路基坡面冲刷研究中的关键内容之一。坡面冲刷强度在数值上等于坡面流挟沙冲刷能力 ,包括推移冲刷和悬移冲刷两部分。水流中土颗粒在运动中相互碰撞时 ,会产生颗粒剪切力和粒间离散力 ,结合能量守恒原理 ,推导得出坡面流推移冲刷强度。土颗粒在水流中下沉时 ,土颗粒重心作为一个整体基本保持在一定高度 ,那么水流必须以与沉速相同的速度将土颗粒举起 ,推导得出坡面流悬移冲刷强度。以南方花岗岩风化层路堑边坡为例 ,对路堑坡面冲刷强度进行了计算 ,计算结果可供路基边坡设计和养护参考。

When the railway and highway are constructed in granite region in the south and loess region in the south, the subgrade slope is often than not subject to serious scouring. And the intensity of scouring is one of the main research issues for the study. The intensity of scouring on the slope is equivalent to flow capacity, with the sand being carried. That breaks down into shift scouring and suspension scouring. When the granules hitting one another in the process of flowing, they generate granule shearing force and discrete force. According to the law of conservation of energy, the pushing scouring intensity on the slope can be deduced. When the soil granules are sinking during the flow the center of gravity of the granules as integrity shall keep staying at a certain height. The flow must use the same speed to support the granules as the sinking speed. So the suspension scouring intensity of the slope flow can be deduced. Taking the filling slope of weathered granite in the south for example, the scouring intensity of the filling slope is calculated. The results of the calculation can be provided as a reference to the subgrade slope design and maintenance.