ABSTRACT
For each individual project, it is a technical challenge to build a tunnel under difficult groundwater conditions. Indeed, a disaster occurred to Marc Isambard Brunel as he built the Thames-Tunnel (1825-1842). In conventional NATM tunneling a lowering of the groundwater or alternatively a soil freezing is essential. In this paper, however, conventional NATM tunneling is not to be discussed; instead the use of a closed shield will be subject of this paper.
