A new concrete colossus towers over the Grand-Rivière-Nord-Ouest valley on the outskirts of Port-Louis, the capital of Mauritius. This bridge, the only one of its kind in this part of the Indian Ocean, is the ‘SAJ’ bridge on the A1-M1 motorway designed by SYSTRA IBT. It links the communities of Sorèze and Coromandel to ease the flow of road traffic between the centre and west of the country, and to strengthen exchanges between the capital and its outskirts.
Our teams carried out all the studies, from detailed structural design to testing, including drainage studies, construction plans, and lightning protection.
We are delighted that the bridge has been officially inaugurated by the Mauritian authorities. This is the culmination of five years’ work by our design teams, and almost a decade’s work by the project teams, since the preliminary studies phase. At the beginning of February, we successfully concluded the final stage of the project with the bridge loading tests. I would like to extend my warmest thanks to everyone who has contributed to this extraordinary project.
Sanad Shamsan, Project Director, SYSTRA IBT
AN ICONIC BRIDGE
Visually, the architecture of this 330-metre bridge has been designed to make it one of the country’s most emblematic structures. And technically, the choice of an extradosed bridge supported by cable-stays ensures optimum structural stability and balanced load distribution.
The main technical challenge was the construction of the deck, consisting of a single box girder. Cast in situ balanced cantilever method, this deck is made with asymmetrical spans and constructed using additional temporary stays, designed to support the extra length of the side spans. With just 2 pylons, the bridge links the two cliffs while minimising its impact on the environment.
Cyclone proof
Given its geographical location, the A1-M1 bridge will also have to withstand the local wind climate. A detailed wind climate study of the project site was therefore carried out to investigate the impact of cyclones, both during construction and in service, and to derive the wind buffeting loads for the bridge design.
*The name Sir Anerood Jugnauth is that of an ex-prime minister and president of the Republic of Mauritius.