GEOTECHNICAL ASPECTS of TUNNELLING
Ongoing rapid urbanization has led to a use up of available free surface space causing a continuously increasing need for subsurface transportation and storage structures. Moreover, major projects of several kilometers length to underpass rivers, channels and mountains have been forced in recent time to improve the efficiency of railway and road infrastructure projects. Hence, the realization of tunneling projects has become more important than ever. It is the need for increasing the length and the diameter of such tunneling projects which claims a demanding design task for both geotechnical and structural engineering. In order to design a tunnel, tunnel heading stability, surface settlements and structural forces in linings have to be assessed. Based on two case studies of the Rennsteig motorway tunnel in Thuringia and the Steinhaldenfeld subway tunnel in Stuttgart, Germany, this paper will highlight the contribution of geotechnical analysis to arrive at a reliable tunnel design.