Constantine-skikda tunnels

Algeria, Constantine-Skikda
Nonwoven geotextiles as drainage and separation layer on tunnels

Problem:
the Est-West highway represents one of the largest infrastructure projects in the history of Algeria: it links the western border (Morocco side) to the eastern border (Tunisia side).
The project has been divided into three parts: East lot, Centre lot, and West lot. Along its route a variety of soils constitute the foundation and outline of project.
Specifically, the section from Constantine to the border with Tunisia has mountainous sections with slopes subject to landslides that require significant infrastructure works.
In just a single lot, 3 rockfall tunnels of various lengths have been built in order to secure a section of highway that runs between two very steep slopes.

Solution:
the solution presented was to use Geodren®PPSEX 500, a 500 g/m2 polypropylene needlepunched geotextile for rainfall drainage and separation functions, between top soil and tunnel surface.
Rainfalls were drained through the plane of the geotextile thanks to its special raw materials and absence of thermic treatments.
Geodren®PPSEX 500 reached better drainage capacity performance in comparison to standard products, better chemical resistance and durability.