Rohbaustollen Angath - Line 30201/10104 / National Border - Wörgl / Wörgl - Innsbruck 4 - track extension Schaftenau - Radfeld - Construction lot T4.2 Angath roughwork tunnel Rock mechanical and mineralogical-petrographic laboratory investigations

The "Angath tunnel" serves as a later rescue tunnel in the course of the main construction measures for the Angerberg tunnel. In addition, the excavation of the pilot tunnel will serve to explore the geological/geotechnical conditions of the Unterangerberg formation. The Unterangerberg formation, which consists mainly of tertiary sedimentary deposits and represents one of the few occurrences of molasse sediments within the Alps, will be penetrated. Alternating layers of highly anisotropic and differently weathered clay, marl and sandstones dominate the rock mass. The interbedding results in frequent, small-scale changes in strength and stiffness. The rock mass is also (highly) variable in contact with water and shows increased swelling potential in some areas (clay mineral). During the tunnel drive, rock samples are taken from the face and from exploratory drillings for laboratory tests. The results of the laboratory tests serve as a basis for further tunnel design and for target/actual comparisons between the construction forecast and the conditions actually encountered.