公路黄土坝式路堤蓄水位分析

Pool level analysis of highway loess dam embankment

为分析公路黄土坝式路堤涵洞闲置原因,针对路堤上游蓄水的U型沟谷几何边界条件建立库区模型,根据路堤蓄水补充损失特点建立库水补充损失模式,利用渗流力学、蒸发理论得到蓄水位算式,通过调研与实测选定路堤模拟参数进行了水位计算,并与已建的路堤蓄水实际情况进行了对比验证。分析结果表明:不考虑泥沙影响,在正常的年降雨入库量条件下,无放水的公路黄土坝式路堤具有正常蓄水上限水位,即理想均值水位和上限高水位;上限水位的存在与蓄水时间没有关系;上限高水位小于涵洞底部标高是涵洞闲置的本质原因;实际设计时应注意上限高水位对滞洪库容的影响。

In order to find out the idle reasons of loess dam embankment culvert for highway, the calculation model of reservoir was established according to the geological boundary conditions of U-shaped gully for embankment upriver water storage. In out water modes were set up based on the characteristics of embankment in-out water. Pool level formulae were proposed based on seepage mechanics and evaporation theory. Water level was calculated with simulated embankment parameters from investigation and actual measuring, and was contrasted with the actual situation of embankment water storage. Analysis result shows that highway loess dam embankment is of upper limit water levels without drainage and the influences of mud and sand in normal rainfall, that are ideal average water level and upper limit peak water level. The upper limit water level is not related with storing time. The essence reason for idle culvert is that upper limit peak water level is less than the bottom elevation of culvert, and the effect of upper limit peak water level on balancing storage should be considered in actual design. 4 tabs, 9 figs, 16 refs.