The work is a basic component of the general programme for the development and extension of the infrastructures of the city of Algiers and its hinterland.
The underground channel in El Harrach, called “Rive Gauche” due to its location on the left bank of the river, is the major work of the whole sewers network of the district by its primary function.
The work has the capacity to carry off the sewage being discharged by 750.000 inhabitants equivalent.
The work is made up by the following structures: underground channel executed with tunneling method with excavation diameter 4.02 meters; no. 2 syphons made up with precast reinforced concrete pipes and no. 2 raising stations with all relevant operational and control devices.
The excavation of the underground channel has been executed with a single shield TBM provided with pre-lining placing devices. The pre-lining has been made up with steel ribs and horizontal precast concrete units.