Requirements for ground investigations in shield tunnelling

The success of a tunnel project depends on successfully overcoming the ground conditions and the geological risks. Despite this basic fact, the production of technical regulations and guidelines, the further development of machine technology and improving methods of surveying and control, mishaps still often occur during tunnel drives, affecting either the tunnel itself or the surroundings, e.g. existing infrastructure or buildings. The causes are often multifaceted but can almost always be attributed to the existing ground conditions, which had not been appropriately determined, described, or considered in the design, or taken into account during construction. The following explanations describe the risks inherent in ground conditions and show how these risks can be countered by appropriate ground investigations for tunnelling. © 2010 Ernst & Sohn Verlag fur Architektur und technische Wissenschaften GmbH & Co. KG, Berlin.