Veneer Reinforcement for Landfill Capping System

Landfill capping generally involves covering the landfill cell with a thick layer of clay, followed by a protective geomembrane liner, then a layer of soil over top as a veneer cover. Occasionally, the soil veneer slides down the slopes and breaks apart because of its weight, but climactic conditions and slope steepness are also contributing factors. When this happens, it puts a strain on the geomembrane liner increasing the risk of rupture. These were real risk considerations in the design of a capping system for a landfill in Queenstown, New Zealand, which featured steep slopes (2.5:1) and was located in an area with high winds funneling through a gorge.

Titan Solution

Titan's Pyramid Grid™ was used as a veneer reinforcement solution placed directly over the LLDPE geomembrane then covered with 500mm of scalping (a protective stone layer) and 150mm of topsoil mulch. The goal of this solution is to increase the interface friction between the geomembrane and scalping, so tension is in one direction only - along the length of the geogrid. This is eliminating transfer of stresses across the width significantly reducing the strain on the liner.

Pyramid Grid™ is a high-strength uniaxial polyester geogrid engineered for soil reinforcement, offering exceptional tensile capacity, durability, and stability in demanding construction environments.

Achievement

Using Pyramid Grid™ as a veneer reinforcement solution at this site is mitigating the risk of liner rupture and improving environmental safety. It also allowed for the construction of steeper landfill slopes resulting in increased landfill capacity.