Effect of effective overburden pressure on geomembrane/soil interface transmissivity

Abstract

Fluid flow through a defect in the geomembrane of a composite geomembrane/soil liner (flow rate tests) and interface transmissivity tests between a geomembrane and a soil layer were conducted. The results are compared, and the effect of overburden pressure p′ on the geomembrane/soil interface transmissivity θ and interface thickness tin is investigated. For flow rate tests, the values of θ are back-calculated using the Rowe and Touze-Foltz et al. solutions. With known values of θ, tin is calculated using Newton's viscosity law for fluid flow between two parallel plates. For the conditions considered, it is shown that θ and tin reduce significantly with increasing p′. Comparisons are made between the calculated values of θ and tin and those reported in the literature. It is shown that ignoring the effect of p′ on θ and tin can lead to gross overestimation of these parameters.