The containment systems for landfills need to be judiciously designed, and geosynthetics can play a major role. Geomembranes are often used to seal off the waste mass from the ground on which it is dumped. After the filling is completed to capacity, the landfill is sealed off using layers of appropriate soil and geomembranes. Along the sides, the landfill is contained within earthen dykes which should be stable with a factor of safety higher than conventional, considering the consequences of a breach.
Every landfill cover has two integral components – geomembrane lining and soil cover above the geomembrane. The stability of this soil cover depends on two primary factors.
- The friction between the membrane and soil.
- The slope angle of the landfill surface.
In cases where the friction is high enough, the soil cover remains stable. But in many projects this is not the situation and external reinforcement is required to stabilize the cover. StrataWeb® is an excellent system for confining the soil cover and protecting the membrane below. Installation is rapid and does not cause any damage to the underlying membrane thus maintaining the integrity of the landfill cap.
Steep Slope/ Wall
Conventionally landfills are designed with very flat slopes of the order of 1V:4H to 1V:3H. This entails large stretches of land which in many cases are very expensive or unavailable. Further, contributing to this problem is the location of the landfill which is typically near a city/town, making land more expensive.
Strata reinforced soil solutions allow for landfill facilities to expand vertically as the need for more capacity arises and land is at a premium. Steep slopes from 45o till 70o can be designed with various fascia options. In extreme cases, near vertical concrete block walls can also be engineered.
Strata solutions offer tremendous savings in land costs and reduce construction time.
Access roads leading to a landfill are generally not well maintained and have deposits of the same waste which is to be disposed. Poor access roads lead to lower efficiency and reduced turn around times for dump vehicles.
Strata ground improvement solutions help in improving the bearing capacity of sub grades, reduce differential settlements, are easy and rapid to construct, can be engineered for site specific challenges and can make use of locally available materials.
StrataGrid™ biaxial (PP) works on the principles of interlocking of particles and behaves like a 2D rigid mat. This product can be used for moderate ground improvement challenges.
StrataWeb® is very effective and feasible in cases where the subgrade is very soft or the loads are very high. As it confines the infilled material it provides a stiff base layer for the access road. StrataWeb® facilitates the use of various kinds of infill materials such as construction debris, riprap, recycled asphalt pavement etc.