The RN77 highway connects the Djendjene port and the East-West highway. The alignment runs through the Djendjene valley, in North-South direction, from the coastline to the plateau up to El Eulma, crossing the irregular and steep mountain area of Texenna (Petit Kabilye’s Chain). The alignment includes main and subordinated works, more than 100 viaducts, a 1750m-long tunnel, embankments and up to 90m high large excavations. The project faces several critical and technical aspects mainly due to morphological (steep and irregular slopes) and geological/geotechnical conditions (complex geological formations, tectonically active area). Several interferences with pre-existing road (National Road RN77) and ongoing civil works construction (Tabellout dam) are presents.

Detailed Design: geological and geotechnical investigations, tunnel design, retaining walls, foundations for viaducts design and soil mechanics characterization.