El Azhar road tunnel—Cairo's new frontier

The historic Islamic centre of Cairo is now a more pleasant place to be thanks to a new, state-of-the-art road tunnel through the middle of one of the world's largest cities. The new 2·4 km long, twin-bore El Azhar road tunnel was designed and built in just 40 months to Europe's highest fire-safety standard. It has pioneered the use of a reinforced fire lining, which protects the tunnel structure from temperatures in excess of 200°C and thus prevents spalling. It also has an unusual escape system—rather than escaping through cross-passages between bores, users slide down into a safe passage beneath each road deck. This paper describes the design and construction of this innovative, fast-track project.