The construction of the new tunnel designed by Alpina allowed, through the underpass of the Rabat fortress, to divert the traffic under one of the city’s main thoroughfares, separating the Kasbah from Medina.

The tunnel extends from the Bab Al Bahr roundabout (Bouregreg river side) up to the Surf Club (Ocean side), for 1015 m.

The difficulty in working under historical complex with reduced heights was resolved by  transferring initially the loads to the deep through a temporary support (micro-piles). Other significant problems were addressed and resolved, mainly related to the presence of the water table and to the closeness between the two natural tunnels carried out.

On site testing and sophisticated 3D numerical analysis, combined with a complex monitoring, made it possible to control successfully the different phases of execution.