Design and construction of NATM underground station tunnel by using the forepoling method in difficult conditions for Athens Metro

Agios Savas underground complex is a part of the new extension LINE 3 of Athens’ metro. The project is considered to be very complicated (Figs 1, 2), since it contains an underground station of 110 m in length (1), the main building (2) close to the station tunnel and a cut&cover dome (3) which will be connected with the main building via an underground cross gallery (4). Furthermore, four underground inclined galleries (5) with stairs are foreseen for the transportation between the dome, the station and the main building.