Tunnel seismics

ISIS

Person in charge: Dr. Ruediger Giese

 

For a safe and efficient construction of underground structures (e.g., tunnels, galleries, caverns, etc.) it is essential to be provided with a most detailed exploration of the subsurface. Direct observations from boreholes can be ideally complemented with geophysical investigations. Seismic measurements have proven to be particularly appropriate. They are being applied successfully from the surface for shallow structures.

In section 5.1, the components of an Integrated Seismic Imaging System (ISIS) for exploration ahead of a construction are being developed. The ISIS components are:

Seismic sources:

A pneumatic hammer to generate a strong and repetitive impact signal; a magnetostriktive vibration source to generate a repetitive high resolution sweep signal.

Seismic receivers:

Three-component geophones are fit into the tips of anchor rods.

Processing and interpretation software:

The ISIS software provides tools for seismic data processing, and for the integrated imaging and interpretation of the observed data and other geological and geotechnical parameters.

The seismic sources and receivers are constructed and manufactured by the geotechnical development workshop of the GFZ Potsdam.

Since March 2000, the system has been used within several campaigns along with the construction of the Gotthard Base Tunnel (Switzerland).

ISIS INTERN

Cooperations:

The development of the ISIS components and their application to measurements is supported by the following partners:

Amberg Technologies AG
Christian-Albrechts-Universität Kiel
FH Brandenburg
Freie Universität Berlin
Herrenknecht AG
Institut für Geowissenschaftliche Gemeinschaftsaufgaben Hannover (GGA)
TU Bergakademie Freiberg

References:

Giese, R., Klose, C., and Borm, G. (2005): In situ seismic investigations of fault zones in the Leventina Gneiss Complex of the Swiss Central Alps. In: Harvey, P. K., Brewer, T. S., Pezard, P. & Petrov, V. A. (eds). Petrophysical Properties of Crystalline Rocks. Geological Society, London, Special Publications, 240, 15 - 24.

Lüth, S., Buske, S., Giese, R., Goertz, A., 2005. Fresnel volume migration of multicomponent data. Geophysics 70(6), 121-129.

Borm, G. & Giese, R. (2004): Hochauflösende seismische Gebirgserkundung beim Tunnelbau im Festgestein. Geotechnik 27, Nr. 2, 164 - 167.

Giese, R., Dickmann, Th., Eppler, Th. and Lüth, S., 2006, Seismic tomography to investigate the tunnel surroundings of the Side Gallery West of the multifunctional station Faido. In: Geologie und Geotechnik der Basistunnels am Gotthard und Lötschberg, vdf Hochschulverlag AG an der ETH Zürich, 145 -154.