Highway - Ruhengeri to Gisenyi Road
Strabag International GmbH
TR Engineering & HUESKER Synthetic GmbH
The existing Ruhengeri to Gisenyi road in the North Western part of Rwanda winds along steep mountainous hillsides. The 40 years old road is the main transit route for goods into the Democratic Republic of the Congo (RDC). An increase in traffic volume of heavy goods vehicles and the general deterioration of the existing road have resulted in the edges of the pavement construction falling away from the main carriageway. Additionally, some parts of the existing carriageway had insufficient highway width and a lack of suitable safety barrier. Funding was obtained from the European Commission to reconstruct and improve the quality of the road with respect to its long-term stability and safety.
The carriageway required widening by approximately 1 m with an additional 2 m ‘hard shoulder’ and safety barrier. Of the various options investigated by the client, the geosynthetic reinforced soil (GRS) system for the steep slope was the most eco-friendly and cost-effective solution. The widening requirements resulted in the pavement extending into the existing steep hillside. A 70° steep reinforced soil slope raised to a maximum height of 8 m. The slope was formed using the simple wraparound type structure. The green faced reinforced soil structure was deemed the most appropriate, economical and sustainable solution. The road re-construction and upgrade commenced in July 2007 and was completed in March 2010. The geosynthetic reinforced soil slope section was constructed in 2009.
• Easy construction, local manual labour
• Economical solution compare to traditional structures (e.g. gravity mass concrete retaining walls)
• Very flexible solution in construction, in engineering and landscaping
• Quick and easy allowing on-time project completion
• No concrete or steel materials needed which are very cost intensive in Africa
• The geogrid allows the re-use of existing local fill material
• Excellent integration with the exiting environment
• Environmental solution- lower CO2 emissions compared to alternative solutions