Segmental retaining walls for Ouagadougou interchange
Location of work/project:
Ouagadougou - Burkina Faso
The use of modular block facing in combination with geosynthetics to reinforce the slopes is one of the most current technics. It solves the stability problems of the embankment and offers elegant solutions for the phasing of structures in the complex architecture of the northern interchange of Ouagadougou in Burkina Faso.
Enable the fluidity of urban traffic is a challenge everywhere in the world around big cities. In the urban areas of the city of Ouagadougou in Burkina Faso, the project of northern interchange aims to allow a good structuring of the network of roads and to relieve roads congestion. The northern interchange consists of a network of access roads that need the construction of embankments, whose height varied between 2.4m and 9 m, and bridges with the inherent difficulties of the urban area such as the limited available space.
To stiffen the slopes and therefore limit the soil occupation and backfill purchase that would increase the cost of the earthworks, the solution chosen by the client consists of retaining walls made of concrete modular blocks at the facing (Atalus elements) and reinforcement with TenCate Geolon® PET geotextiles.
The use of modular block facing in combination with geosynthetics to reinforce the slopes is one of the most current technics. It solves the stability problems of the embankment and offers elegant solutions for the phasing of structures in complex architecture. The flexibility of the system allows to follow curves and complex wall geometry with vertical connection with civil engineering structures. Almost all the geometrical scenarios were applied on this construction site, the longest wall reaches 500 m and a maximal height of 8.6 m, with the shortest radius of curvature being 8 m.
This technique is fully adapted to the constrain of the environment and makes it possible to use different soil types to adapt to the local technical and economic context.
On Ouagadougou interchange, more than 20 000 m² of facing and 200 000 m² of TenCate Geolon® PET were installed. Environmental integration, the ease of installation and the cost effectiveness lead the choice of the solution.