Algiers Metro Line 1 Extension C: El Harrach

Flexible tunnelling in challenging ground conditions

Extending Metro Algiers Line 1 from El Harrach to Ain Naadja 2, this 3-kilometre section fuels the Algerian capital's urban transport infrastructure. Construction of this contract was completed within 44 months and provided a 2,4-kilometre tunnel, two metro stations, one bridge and several ventilation buildings.

Varying geological conditions across Algiers required a flexible tunnelling approach. New Austrian Tunnelling Method (NATM) was selected instead of a tunnel boring machine (TBM), allowing the construction process to adapt to changing ground conditions. Another reason for this decision was the relatively short length of the relevant sections. Both stations were constructed using open-cut methods and partially built beneath a top cover. 

Scope of Work

• NATM tunnelling 
• Open-cut station construction 
• Bridge construction 
• Ventilation buildings