EL AZHAR ROAD TUNNEL, CAIRO'S NEW FRONTIER

Abstract

Cairo's new El Azhar road tunnel is 2.4 km long and was built to the latest standards of fire safety. It follows some of the most prominent roadways in the city, but had to be realigned as more study uncovered hidden elements. The ventilation system was designed to maximize fire safety and minimize pollution from vehicle emissions. High-velocity air jets are central to the design. The tunnel was built with escape chutes and a sacrificial lining that would spare the tunnel from the spalling caused by high temperature fires that lead the concrete to crumble as the water it contains expands from the heat. A system of slides creates easy escape access to ventilation chambers that have ladders to the surface. The tunnel opened in October 2001 after 40 months and now diverts more than 50,000 vehicle movements a day from the historic city center.