ABSTRACT
Launching of a slurry TBM out of any subsurface structure in waterbearing and unstable ground requires special methods to seal the ground during installation of the shield machine. One of the possible techniques is the ground freezing method which was successfully executed at the Lot 3 of the Fern-bahntunnel in Berlin. Due to the special demands of this project, special methods had to be applied for the drilling of the freeze pipes and both freezing and thawing of the ground, the latter in order to extract the freeze pipes prior to the start of the TBM heading.
