Your browser is no longer supported

For the best possible experience using our website we recommend you upgrade to a newer version or another browser.

Your browser appears to have cookies disabled. For the best experience of this website, please enable cookies in your browser

We'll assume we have your consent to use cookies, for example so you won't need to log in each time you visit our site.
Learn more

Monster TBM exits early on Groene Hart rail tunnel

WorldWatch

TUNNELLING ON the Groene Hart Tunnel in the Netherlands was finished in December after two years, several months ahead of schedule.

The 8km tunnel, including approaches, carries the new high speed railway line connecting Brussels, Rotterdam and Amsterdam, beneath a protected area in the middle of the Netherlands - the Groene Hart or Green Heart (European Foundations Spring 2002).

Bouygues Construction, working in joint venture with fellow contractor Koop, decided to build a single bore tunnel almost 15m in diameter with a central separating wall, as an alternative to two smaller diameter tunnels.

The 14.87m diameter, 120m long, 3,100t monster earth pressure balance TBM was designed and built by French firm NFM Technologies, which is part of the German Wirth group.

With a maximum speed of 40mm/minute, the TBM started work in December 2001 and excavated 7,176m - 1.3M. m 3- of ground in just two years.

Clocking up maximum rates of 16m a day and 616m in a month meant the machine emerged at the exit shaft, in a waterlogged polder, far sooner than originally planned.

After draining the polder, work began to dismantle the TBM in January. The process is expected to take another three months.

Have your say

You must sign in to make a comment

Please remember that the submission of any material is governed by our Terms and Conditions and by submitting material you confirm your agreement to these Terms and Conditions. Please note comments made online may also be published in the print edition of New Civil Engineer. Links may be included in your comments but HTML is not permitted.