Equations for calculating the rate of liquid flow through geomembrane defects of uniform width and finite or infinite length
Equations pour le calcul des débits de fuite à travers les géomembranes présentant des défauts de largeur uniforme et de longueur finie ou infinie
Résumé
This paper presents equations for calculating the rate of liquid flow through defects in the geomembrane component of a composite liner. The considered defects have a uniform width and have a length that is finite or infinite. Two types of defects are considered: narrow defects such as tears, cuts and defective seams, and wide defects, such as damaged wrinkles. As a first step, the paper presents a new expression for a previously published equation for the rate of liquid flow through an infinitely long defect in the geomembrane component of a composite liner. This new expression is significantly simpler than the original equation. The new expression is then combined with empirical equations for the rate of liquid flow through a circular defect in the geomembrane component of a composite liner to obtain equations for the rate of liquid flow through a defect of finite length in the geomembrane component of a composite liner. The rate of flow through defects of finite length comprises two components: flow that takes place over the length of the defect and flow that takes place at the two ends of the defect. A parametric study shows that, in most cases, a large fraction of the flow takes place at the ends of defects of finite length. Therefore, it is generally not recommended to do a two-dimensional calculation, thereby neglecting flow at the ends of the defect. Examples of use of the proposed equations are presented.