For more than 40 years, Bouygues Travaux Publics has been contributing to the development of North Africa's biggest city, designing and building the Cairo metro as part of a Franco-Egyptian consortium*. Lines 1 and 2 linking the north and south of the capital have already been completed. Line 3 is still partially under construction and will link the left bank of the Nile to Cairo airport, crossing the capital from east to west and completing the existing network.
*Bouygues Travaux Publics, Vinci Construction Grands Projets, Orascom and Arab Contractors
Focus on the work in progress
Work is underway on phase 3 of line 3, comprising 17.7 kilometres of new line, including around 7 kilometres of tunnels and 15 stations. The fork-shaped route is divided into three sections.
• Section 3A is the base of the fork. It is 4.4 kilometres long and runs exclusively underground, with 4 stations.
• To the north-west, section 3B is 6 kilometres long and includes a viaduct, 4 elevated stations, one above-ground station and one underground station.
• Section 3C, located in the south-west has a viaduct, 3 underground stations, one above-ground station and one elevated station.
A launching operation in a working environment
To build the Cairo metro, our teams are required to work in a densely built-up urban environment, with infrastructures in operation. The project requires genuine adaptation of working methods for certain stages. The deck of the viaduct of batch 3C, built on shoring, is a perfect example! A crane is being used to place the segments on large scaffolding, fixed to the ground, which will support the deck.
The teams had to take into account a technical constraint on a section of several metres! In fact, part of the viaduct stands above an operational metro station, making it impossible to build on shoring. As a result, this section of the deck will have a span measuring no less than 73 metres. The eight segments of this span were prefabricated, lifted and welded approximately 150 metres from the defined location. After several launching operations, the span was put in position above the station, which was closed during the work, in its almost final location.
This viaduct is a strategic infrastructure for Cairo's mobility, as it will link Tawfika station to Cairo University located further south.
Two viaducts, two techniques for installing segments
This project, involving a broad variety of construction techniques, is also an innovation for the region. In fact, two different methods are being used to build the viaducts.
While the viaduct of batch 3C is being built on shoring, the viaduct of batch 3B is being built by a launching girder! It is being built with prefabricated segments, put in position using this machine, allowing the segments to be lifted and assembled to form the deck. Once each section has been completed, the machine moves forward to build the next section. A first in Egypt!
Congratulations to the teams: the batch 3B viaduct has now been finished and a first train has just been tested on the infrastructure!