折线形填埋场排水系统最大浸润线水位深度的计算

Estimation of the maximum saturated depth of landfills with drainage systems composed of two different slopes

在实际的填埋场设计中,存在着排水系统由两段或多段不同坡度的折线段组成的情况,目前对折线形排水系统最大水位深度的准确估算只适用于非常有限的几种情况。依据扩展的Dupuit假设,导出折线形排水系统在自由出流边界条件下的浸润线求解方法。通过案例分析及与Giroud等的计算结果比较,证明所提出的方法是合理和准确的。在此基础上,进行多参数分析。在一般情况下,下坡的最大液面高度取决于总长度、下游坡度及入渗强度。在计算上坡最大水头高度的时候,应该考虑由于下坡积水引起的上下坡交界处的水位。复合排水材料对减少最大水位深度有着重要的意义。

In modern landfills,leachate collection layers often comprise several sections of different slopes.Design methods are only available for limited cases where there is no drain at the connection between two adjacent sections.Based on an extended Dupuit assumption,this paper presented a solution method to calculate the maximum leachate depth for drainage systems composed of two different slopes.By comparison with the results calculated from other methods,the proposed method was shown to be rational and accurate.By means of parametric analysis,it was found that in most cases the maximum leachate depth of the downstream section is determined by the total horizontal length of the two sections,slope of the downstream section and the inflow rate.The leachate depth at the connection between the two sections should be taken into account when calculating the maximum depth of the upstream.Application of geocomposites can significantly reduce the maximum leachate depth of the drainage systems.