Umgang mit dem Baugrundrisiko in der Schweiz, Erfahrungsbericht zum Vortrieb einer Mix‐Schild‐TBM auf der Baustelle Eppenbergtunnel

Abstract

AbstractOn the mix‐shield TBM excavation of the Eppenberg tunnel, unexpected conditions were encountered in both the rock and soil excavations, which resulted in a modified execution of the project. In this case, the openly formulated contract made it possible to take advantage of improvements in the ground and to manage unexpected system behaviour with the right measures in such a way that economical and time‐saving excavation was possible. In all three examples presented in this paper, time is one of the key success factors, because recurring processes result in feedback processes that change the system behaviour more and more rapidly as time goes on. In order to reduce the resulting additional costs and time losses, it is necessary to understand what is happening on site, then evaluate, test and check the possible measures, and finally decide on their implementation in a timely manner. At Eppenberg tunnel, this enabled unexpectedly adverse system behaviour to be overcome in two cases without any major loss of construction time. This was only possible because the responsible persons from all parties involved were able to discuss the situation together and make decisions at short notice.