Spotlight: Giants underground (January 2003)
Sophia Tunnel Rotterdam
Sophia is steadfast...
... and doesn’t budge an inch. That’s not something to be taken for granted, since the soil under the four kilometer long twin tubes of the Sophia Rail Tunnel consists of water-saturated layers of sand. That makes the use of a conventional tunnel-boring machine problematic. In response to this challenge, HOCHTIEF is employing a new kind of technology, a hydroshield TMB.
With this, excavation does not have to be halted for placement of the segments: boring and segment installation
can be carried out in parallel. The only drawback to this method, which is confined to use in soft ground, is
that the TMB is longer and heavier than usual. So keeping it exactly on course demands precision control.
The Sophia Tunnel is part of the 160 kilometer long Betuweroute, currently the biggest infrastructure project in the Netherlands. From 2006, this rail link, which will initially extend all the way to the German border, will provide perceptible relief for highways and ensure less congestion. And that also applies in Lübeck, where HOCHTIEF is completing Germany’s first privately financed infrastructure project, the Herren Tunnel.
