North-South Line, IJ segments

Client:
City of Amsterdam, Service Infrastructure, Traffic and Transport
Location:
Amsterdam
Number of elements:
3
Immersion:
2012
Specials:
Very busy waterway
Projecten - Amsterdam 004
Projecten - IJ tunnel
Projecten - Amsterdam 001
ActCarr_IMG_3236
Projecten - Amsterdam 005
Projecten - Amsterdam 003

Project

Amsterdam’s North-South Line project involves the realisation of an underground connection between Buikslotermeerplein in North Amsterdam and the Zuid/WTC railway station. The planned route passes under both Lake IJ and Amsterdam Central Station.

A total of three tunnel segments with a length of some 141 metres were immersed in the IJ between the southern abutment of Ruijterkade and the abutment of the Sixhaven approach ramp to the north.
In July 2011, the team immersed the CS tunnel segment, with a length of some 136 metres, under the middle tunnel of Amsterdam Central Station (between the existing facade of the station hall and the rear facade on Ruijterkade).
The remaining three tunnel segments were then immersed in the IJ over the course of September and October 2012, establishing a new underwater connection between North Amsterdam and the Central Station area.

Survey Systems

The geometric foundations were established prior to immersion.

The primary measurement system for the positioning of the IJ segments was based on total stations.

In addition, Geocon conducted a number of successful tests with RTK-GPS and LBL.

The visualisation of the levels in the ballast tanks was based on pressure sensors in the immersed joints. 

The loads at the segments’ hoisting points were measured with the aid of wireless sensor probes.

The supporting forces in the hydraulic jack rods were visualised during both the immersion and flooding processes.

Geocon developed a project-specific solution for monitoring the width of the Omega seal.

Further settlement of the immersed tunnel was continuously monitored by an automatic monitoring system.

Innovations

After an intensive preparatory programme, Geocon conducted a number of successful tests in this project that focused on positioning with the aid of LBL.

At the client’s request, we developed a system that allows for the continuous monitoring of the joint widths between the different sections of a tunnel segment during transport and immersion.

The settlement of the different segments was subject to fully automated monitoring for more than one year after immersion.

Tunnel 'Wendy' immersed in IJ-water

ws0gst09ukc

Timelapse immersion tunnelelement "Nienke"

MtFJ8H5-xo8