Gamsjager H.,Ed. Zublin AG |
Satina J.,Ed. Zublin AG
Geomechanik und Tunnelbau | Year: 2013
Special situations can pose an extraordinary degree of difficulty and risk levels when tunnelling in soft ground, formations with soft ground character or at transitions to soft ground, especially when combined with low overburden, urban constraints or fault zones. Dealing with such situations is therefore of vital importance, to identify the situation correctly already during site investigation and design phase in order to derive the appropriate technical measures or approach. In addition, these situations are a particular area of conflict in tunnelling contracts when changes in ground conditions with high risk levels are encountered during execution of the works. The paper deals with circumstances and constraints of high risk situations in connection with soft ground tunnelling according to experience. It tries to identify and explain causal chains and interactions for such situations. © 2013 Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG, Berlin.