Liquid Flow Through Composite Liners due to Geomembrane Defects: Nonuniform Hydraulic Transmissivity at the Liner Interface

Rates of liquid flow through composite liners are intimately linked with the existence of a transmissive layer between the soil liner and the geomembrane. The aim of this paper is to propose analytical solutions for estimating the rate of liquid flow through composite liners for the case where two zones of different hydraulic transmissivities coexist in the transmissive layer. Solutions are given for both the axi-symmetric and two-dimensional cases. The development of these analytical solutions is directly based on solutions that have been proposed previously for uniform hydraulic transmissivity. Results tend to show, for the simple cases evaluated, that, in situations where there is variable hydraulic transmissivity, neglecting the variability can result in a significant overestimation of the rate of liquid flow. This preliminary approach shows the importance of taking into account a realistic distribution of hydraulic transmissivity in attempts to estimate the rate of liquid flow through composite liner...