植被密度对降低土堤下游边坡河床剪应力的影响研究

Study on the effect of vegetation density on reducing the shear stress of the riverbed in the downstream slope of the earth embankment

为最大限度减少自然灾害的影响、实现农业生产目标,需要对受损的堤坝进行可持续和低成本的维护。其中河床剪应力是造成堤坝溃决的主要因素之一,为了减少河床剪应力对下游边坡、坡脚和河床的侵蚀,本文通过水槽进行相关试验。考虑到下游坡面流量不同,因此选用3种流量,对4种不同密度的植被进行试验,研究明渠溢流过程中植被的水力特性。结果表明,种植植被可显著降低河床剪应力,在土质路堤的下游斜坡处种植较密集的植被时,也可减少侵蚀,降低漫顶水流造成的损害。

To minimize the impact of natural disasters and achieve agricultural production goals,sustainable and low-cost maintenance of damaged levees is required.Among them,the shear stress of the river bed is one of the main factors causing the failure of the dam.In order to reduce the erosion of the river bed shear stress on the downstream slope,toe of the slope and the river bed,this paper conducts relevant experiments through the flume.Considering the different flow rates on the downstream slope,three kinds of flow rates were selected,and four kinds of vegetation with different densities were tested to study the hydraulic characteristics of the vegetation during the overflow process of the open channel.The results show that planting vegetation can significantly reduce the shear stress of the river bed,and when denser vegetation is planted on the downstream slope of the soil embankment,it can also reduce erosion and reduce the damage caused by the overflowing water flow.