ABSTRACT
The overburden is nevertheless a fundamental aspect: maximum 20 m at the tunnel axis and approximately 4 m by crossing the garden of the Kasbah. Main aspect remains undoubtedly the proximity of especially the ancient walls and towers of the Kasbah des Oudayas: the western walls, towers and buildings at the Esplanade portal, are situated immediately above the tunnel. A special construction method needed to be engineered in order to excavate the tunnel’s culvert exactly underneath these ones. The works for stabilising the foundations of these buildings are actually ongoing.
