Randstadrail Rotterdam Staten Tunnel

The project involved the construction of a metro tunnel comprising two single-track tunnel tubes beneath Rotterdam city centre, carried out by the joint venture comprising ZÜBLIN, Walter Bau and Dura Vermeer. The project also included the Blijdorp metro station, the connection to Rotterdam Central Station and all associated building services.

The tunnels are divided into two sections and are interconnected by five cross-passages, constructed using traditional excavation, ground freezing and shotcrete. The construction required extensive foundation works, such as 31,000 m² of diaphragm wall structures, 40,000 m³ of lime-cement columns and 14,000 m³ of jet grout.

The subsoil consisted mainly of Pleistocene sand layers, with softer Holocene clay near the shafts, which was stabilised in advance. The entire tunnel alignment lies below the water table, with water pressures of up to three bar, which necessitated specific construction and stabilisation techniques.