A3 highway reinforced soil slope

Italy, Lauria (PZ)
PET woven geogrids with PVC coating as a structural element for reinforced soil slope construction

Problem:
in south-western Italy, near Salerno, there are large infrastructure projects in progress or undergoing modernization.
Among these, there is the expansion of the A3 Salerno-Reggio Calabria highway.
This section includes Type 1/A modernization and upgrading works according to the National Research Center (C.N.R./80) for the section from km 108+00 to km 139+00. Here, Geosintex supplied SIS Scpa materials, technology and technical support for soil reinforcement works, including the works referred to as TR02 (year 2009), set on highly complex land in terms of its stratigraphy and in an area subject to significant seismic activity.

Solution:
the solution adopted was to perform a soil reinforcement with Edilgrid®, a PET woven geogrid with PVC coating, in order to guarantee the stability of the embankment while allowing excellent integration in the surrounding environment.
Edilgrid® has a tensile strength of 55-80-110 kN/m, low tensile strain at failure, provides low tensile creep, good durability and mechanical protection, and is extremely simple and quick to lay.
The TR02 reinforced embankment belongs to the reinforced slopes category which is characterized by slope angle of 63° and 65 cm thick soil layers.
It consists of two slopes.
The first one starts at ground level with a height of 5,20 m, followed by a 6 m bank where a service road passes. The second one has a height of 5,20 m.
At the summit of the second slope there is a small horizontal bank, about 3,50 m wide, which is topped by a 34° slope with maximum height of 14 m. The reinforced soil has a linear extension of about 500 m, with a total surface area of 3.600 m2.
As a result, the face is completely re-grown and the works blend seamlessly with the surrounding environment. The use of Edilgrid® perfectly addresses the structural constraints giving by soil stratigrafy and its seismic activity.