Henri Konan Bédié Bridge

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Context Spanning the Ebrié lagoon, the Henri Konan Bédié Bridge is the third bridge to link the northern and southern districts of Abidjan. Opened in late 2014, it has been responsible for decongesting the Houphouet-Boigny Bridge (54,000 vehicles per day) and the Charles De Gaulle Bridge (130,000 vehicles per day). The inhabitants of Abidjan have suffered from a shortage of transport facilities, but they now enjoy easier traffic conditions. The benefit has been estimated as saving 1.8 million hours of congestion per year. The bridge links the residential district of Riviera and the popular Marcory district. It avoids drivers needing to take a 10-kilometre bypass and reduces journey-times by half an hour. The bridge will also decongest the neighbouring hinterland. Challenge The project was more than a bridge; it also included a 6.7-kilometre stretch of highway (including the access roads). The bridge itself consists of three lanes in each direction, a 21-gate toll plaza and an interchange that would not disgrace a large American city, with 16 decks on three levels. Project Our subsidiary Bouygues Travaux Publics is the leading shareholder of the concession company, Socoprim, which designed and built the infrastructure and will operate the highway and bridge for 30 years. VSL contributed its technical expertise by carrying out the post-tensioning of the decks of the interchange and the caissons of the bridge. Innovation The project teams had to contend with two particularly delicate operations when it came to driving and concreting the piers of the bridge in the lagoon. There was an enormous challenge in ensuring a continuous supply of concrete by sea. After roughly a year’s work, the 62 piers – 2 metres in diameter and 85 metres deep – that guaranteed the solidity of the structure could be anchored in the lagoon. The 60 concrete caissons that constitute the deck of the bridge were carried into position by barge and positioned with millimetre accuracy, an extraordinary feat considering that each one weighed 1,000 tonnes and was 50 metres long! Environment In compliance with the very strict standards stipulated by the World Bank, the construction site of the Henri Konan Bédié Bridge was managed with social and environmental issues as a priority. Controls of pollution and air and water quality were incorporated in the project. Commitment The construction project attached great importance to its environment, and also to people. When the works began in 2011, following 15 years of civil wars, the project management teams invested heavily in training local employees in a bid to offset the penury of skills in civil engineering. The skills acquired by the site workers following training in the use of equipment, on-site job training and weekly toolbox talks on safety and quality proved useful to them in seeking new employment after completion of the project.

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