Metro North-South Line Amsterdam

As part of the overall Noord-Zuidlijn project, the municipality of Amsterdam has commissioned Ed. Züblin AG in a joint venture with partial lot 4.2.

During the construction preparation phase, the client and contractor worked together under a construction team contract. A design & construct contract was concluded for the subsequent construction work.

The scope of work included the construction of two new single-track tunnel tubes for the Amsterdam metro, each consisting of four sections. The tubes have an internal diameter of 5.82 m and a total length of 6,228 m.

Two hydro-shield TBMs (type SLS) with a drilling diameter of 6.88 meters were used to drive the tunnels. The tunnel tubes were made from segmental rings with a thickness of 35 cm, a pitch of 5+1 and a ring width of 1.5 meters.

The maximum depth of the tunnel is 35 meters.

Special challenges arose due to the undercutting of railroad facilities, which required extensive safety measures. These included, in particular, consolidation and heave injections, which were carried out to stabilize the subsoil and compensate for subsidence. In addition, compensation injections with lengths of up to 35 metres were carried out to minimize the impact of the tunnel drive on the surrounding area.

The ground freezing method was used to create cross-passages, which enabled safe and controlled driving in difficult geological conditions. For the emergency exits, caisson-type lowering shafts were constructed, which were also secured using targeted grouting measures.