New investigations on swelling rocks in the Belchen tunnel, Switzerland

Severe problems with swelling rocks in the Belchen tunnel have lead to several field and laboratory investigations concerning this problem in relation to reconstruction of parts of the tunnel. The latest investigations include theoretical considerations concerning the maximum swelling stress of the “anhydrite swelling”, drillings, laboratory measurements of swelling strain and stress, petrographical and mineralogical investigations. The conversion of anhydrite into gypsum in the anhydrite containing shale is of special interest. Ernsthafte Probleme mit quellfähigen Gesteinen im Belchentunnel haben zu mehreren Feld- und Laboruntersuchungen in Verbindung mit Sanierungs- und Erneuerungsarbeiten geführt. Die…