Upgrade of a historic transit route through Algeria


Strengthening and improvement of safety on the heavily-trafficked transit route from the Algerian coast and port of Bajaia to the industrial and raw materials centres in the interior of the country. Comprehensive upgrade and widening works are proposed over the entire route, including three tunnels.

The existing alignment, built in the 1870s, is highly exposed to the terrain of the Kherrata gorge, with vertical and overhanging cuttings. The important north-south connection to the coast will be strengthened and upgraded. Three tunnels of length 515m, 240m and 375m are to be constructed. The project area lies predominantly in limestone. Tunnel T01 lies partially in travertine. Along the existing road, there are areas of blocky breccias, weathered slopes and tectonic rifts with low rock cover to the tunnel.


  • Complete detailed design, including excavation sequences, cross section development and permanent lining
  • Checking of all relevant aspects for the design, e.g. geology, hydrogeology, construction techniques, programme and safety
  • Feasibility and options studies in the challenging conditions of the Kherrata gorge

  • Comprehensive advice to the contractor on site and subsequent optimisation of the design
  • Detailed logging and investigations, including at the highly exposed portal areas, to allow a safe, flexible and detailed design

Project Facts

  • Project

    Upgrade of a historic transit route through Algeria

  • Client

    Özgün Construcution

  • Function

    Upgrade of a historic transit route in Algeria

  • Technical Facts

    3 single-bore, two-lane road tunnels

Print Factsheet

Contact Person