Three types geosynthetics, originating from the production companies of TenCate Geosynthetics in Linz (Austria), Bezons (France) and Almelo, have been used in extending the runway of the international airport Ain Arnat in Sétif (Algeria). More than 100,000 m² of non-wovens, wovens and geogrids have been used in realizing a sustainable and cost-efficient solution. Furthermore TenCate has offered technical support.
Ain Arnat (Sétif International Airport) is located 200 km southeast of Algiers, the capital of Algeria. To enable following generations of large aircraft to land and take off, it is necessary to extend the runway to 3200 metres. The soft soils in the low-lying area where the extension is to be carried out is a critical issue. To ensure the safe behaviour of the embankments (up to 13 m high), it was decided to use TenCate geosynthetics: 33,000 m² of TenCate Bidim® non-woven (for drainage trenches and blankets to prevent clogging); 34,000 m² of TenCate Geolon® wovens (as strong reinforcement at the embankment base); and 40,000 m² of TenCate Miragrid geogrid (to increase stress diffusion on fills).
TenCate Bidim® S72 is manufactured in Bezons and is a non-woven for filtration and separation. The material is used mainly in hydraulic constructions where stringent filter criteria apply or extreme mechanical stresses are expected. TenCate Geolon® PET 400 is a high strength woven geosynthetic from Almelo. It is especially applied as base reinforcement for earth courses on weak soils and piled foundations. It is designed for long service, in most cases more than 100 years. TenCate Miragrid GX 55/55 are geogrids from Linz. They are specially designed for reinforcing coarse-grained non-cohesive material.
As far as specifications are concerned, the materials can be accurately tailored to project and customer through flexible production. This means the right product in the right place at the right time. An external laboratory has successfully conducted tests on the performance of the geosynthetics. The local distributor and TenCate sales and engineers are providing technical support in the successive phases of the design and the installation. In this complex geotechnical context, these fruitful advices were highly appreciated by the different actors of the project. The work has caused no disruption at all to air traffic.
On delivery during the course of 2012, the extension of the Ain Arnat runway will serve as a good reference for future comparable technical applications.