Tunnel immersion underneath a historic monument and the river IJ, Amsterdam North-South line
In Amsterdam a metro line is being build from North to South. Part of the metro line is realized using immersion techniques. Part of the immersion is done underneath the historic building of Amsterdam Central Station. To make this possible the station building, the railway tracks and platforms had to be given a new foundation and a bridge construction was necessary to create the immersion trench. Especially the lack of space and high risks forced the immersion team to several innovative solutions. The other immersed part of the tunnel is situated in the river IJ. Due to heavy shipping traffic closure of the river was restricted to a maximum of 24 hours. Challenge for this part was the curvature of the tunnel elements in both horizontal as vertical direction causing variations of loads and movements during immersion.