Sharra landfill reinforced soil slope

Albania, Sharra 
PET woven geogrids with PVC coating as a structural element for the reinforced slope construction

Problem:
the Sharra landfill is located about 7 km south-east of Tirana and 500/600 m south-west of the town of Sharra. Sharra is separated from Tirana by the hills of Selita and Sharra, about 250/300 m above sea level.
Furthermore, the Sharra hill chain divides the Tirana basin from Ezren, where the landfill is located on the right slope of a small valley, at a height that varies from 95 to 125 m above sea level. The Sharra River is found on the valley bottom. The total surface area of the landfill is about 65,000 m2. The main section of the landfill lies on a limestone and clay stratum, which acts as natural waterproofing.
To complete the limiting perimeter for the waste storage area, an embankment was planned along a 160 m long section with a face slope of 45 ° (landfill side).

Solution:
Solution: The missing perimeter embankment section was constructed using reinforced soil and employing Edilgrid® polyester geogrids with PVC coating, with tensile strength from 35 kN/m to 80 kN/m.
Given the modest face inclination (45°), it was not necessary to use welded metal mesh shuttering. The face was constructed by simply folding up the geogrids (calculating the length of the fold required for each reinforcing layer). At the base of the embankment, an amelioration layer was constructed using granular material, with the dual purpose of creating a regular plane for laying the first geogrid and a drainage layer for any rise water and surface seepage.
The maximum height of the works is 7.30 m. The embankment was sized considering possible truck traffic on the embankment and the seismic acceleration of the area under evaluation.
The reinforcement has a maximum length of 7.00 m with a centre distance of 80 cm. Particular attention was given to the calculation of the overall stability of the works as the soil in front of the embankment (that is, facing the inside of the landfill) has an average slope of 17°.
This required an increase in the anchoring length of the geogrids over and above what is strictly necessary for the internal stability of the structure in order to intercept the deep slip surfaces (called base slip surfaces).