流速对雨洪水漫流下渗的影响分析

流速主要通过影响介质表面淤积层的形成来影响雨洪水下渗,介质表面淤积层的形成跟雨洪水的含沙量和泥沙的颗粒配比有很大关系。为使试验更接近于真实雨洪水下渗,通过以下两方面进行试验设计:一是设计、建立流动浑水模拟下渗仪,该仪器不仅能提供处于稳定流速和扰动状态的浑水,而且还能使浑水以漫流形式均匀流经介质进行垂直一维流下渗;二是收集和分析野外雨洪水,根据分析结果配置不同含沙量和颗粒配比的雨洪水水样。让配置的雨洪水水样分别在不同流速下流经单一中砂介质进行下渗,并在不同时段内测定下渗量,绘制下渗量大小随时间变化的曲线。分析曲线得知雨洪水进行漫流下渗时,在流速和颗粒配比一定时,含沙量越大,下渗量减小的越快,达到稳定所需时间越短,最终的稳定下渗量都相等;在流速和含沙量一定时,泥土百分比越大,下渗量减小的越快,达到稳定所需时间越长,最终的稳定下渗量越小;在含沙量和颗粒配比一定时,流速越大,下渗量减小的越慢,达到稳定下渗量所需时间越长,最终的稳定下渗量越大。

Analysis for the impact of velocity on controlled flooding percolation

Flow impacts flooding percolation mainly by infecting the formation of the sediment layer of media surface which has an important relation with the proportion of sandiness and silt.In order to make the test closer to the real rain flood infiltration,the experimental design includes the two aspects that is as the following: First,establishing infiltration device of mobile muddy water simulation which is not only able to provide a stable flow rate and disturbances in the state of the muddy water,but also make...