Evaluation of the rate of leakage through composite liners

A critical reappraisal of residual soils as compacted soil liners

“…Fluet et al [40] reported that the utilization of CSLs as single liner systems in construction/ demolition debris landfills could be recommended as an effective liner material to prevent leachate migration. Also, studies by [45,[90][91][92][93] have revealed that seepage rates through geomembrane liners with holes can be greatly minimized if the geomembrane is placed in direct contact with a compacted soil layer of low permeability, to form a composite liner. Nowadays, because of the effective nature of composite liner systems, an increasing number of solid waste landfill operators and designers have resorted to this technique to ensure long-term protection of human health and the environment as well as meet the required standards for landfill liner systems [40].…”

Suitability of Irbid Clay as Compacted Liners for Landfill, Jordan

“…The hydraulic conductivity of the compacted soil samples was determined at optimum and 3% wet of optimum water content by using the falling head apparatus in accordance with [5]. The results of the hydraulic conductivity tests conducted at optimum and 3% wet of op- [10,11] for the rate of leakage through a circular hole in the geomembrane component of a composite liner. These equations are also presented by [12].…”

Numerical model for determining the wetting front in a clay layer of a leaking composite barrier

“…Leakage through a composite barrier result from flow through small slits in the geomembrane and subsequently through the soil layer, or from vapor transmission through the geomembrane and again subsequently through the soil layer. In the case of leakage through a composite barrier, vapor transmission through intact geomembranes is significantly less than the rate of leakage through an imperfection in a geomembrane placed on a high hydraulic conductivity soil (Brown et al , 1987;Jayawickrama et al , 1988;Bonaparte et al , 1989;Giroud and Bonaparte, 1989b;Giroud et al, 1989). Giroud and Bonaparte (1989 a) determined that the rate of leakage due to vapor transmission through an intact geomembrane is not significantly different whether the geomembrane is placed on a low hydraulic conductivity soil or a high hydraulic conductivity soil.…”

“…The rate of leakage in the case of a composite barrier is affected by the types of damage in the geomembrane, e. g. , slit hole, pin hole, and punch hole (Brown et al 1987). Previous research work indicates that a key factor influencing the rate of leakage through a composite barrier is the quality of contact between the geomembrane and low hydraulic conductivity soil (Giroud and Bonaparte 1989 a, b;Giroud et al 1989). Giroud and Bonaparte (1986) Composite barrier provided a relationship between the size of the leakage beneath the geomembrane and the head of the leachate level above the geomembrane.…”

“…Flow through composite barriers with damaged geomembranes has not been well established. However, Giroud et al (1989) Objectives of this research were: (1) to study the progress of a wetting front in a soil barrier without a geomembrane (one-dimensional nonstationary unsaturated flow), (2) to analyze the progress of a wetting front in a composite barrier with a geomembrane damaged during installation at the site or during manufacturing process (two-dimensional nonstationary, unsaturated flow), (3) to predict in both cases, the time in which the wetting front reaches the leachate collection and detection, (4) to develop a finite element computer program that is capable of simulating flow through damaged geomembranes, and (5) to study different composite barrier scenarios with damaged geomembranes which illustrates the usefulness of the developed program.…”