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

Betty and Liva win out

By next February two full face earth pressure balance tunnelling machines will have completed a near three year battle through difficult ground beneath Copenhagen's main streets to achieve all 16.6km of tunnelling for the £600M metro. The twin machines - christened Betty and Liva after local music hall stars - have linked all six city centre underground station boxes and nine deep ventilation shafts, several of which were initially used for construction access.

A slow start, through ground conditions ranging from limestone with bands of hard flint to abrasive glacial sands containing large boulders, led to both machines being strengthened and their heads, each with 40 cutter discs, being modified. Recent drive rates of 248m of completed 5.2m diameter tunnel a week are claimed as world records for this type of machine and the metro's first city centre phase should open in autumn 2002.

Strict environmental controls have led to fume-free tunnel locomotives; spoil being barged direct to create offshore reclamation and muffled surface plant forming secant piled station boxes tight against city centre buildings. To meet the required zero settlement beneath these timber piled structures, a world leading £10M computerised ground water monitoring regime was set up to ensure the oak piles did not dry out during dewatering of adjacent station boxes.

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.