Deutsch-Schweizerische Zusammenarbeit auf dem Gebiet der Endlagerung: Stofftransport in geklueftetem Fels. Gebirgscharakterisierung im Stollennahbereich. Felslabor Grimsel. Phase 4 Schlussbericht

Abstract

The studies at the Grimsel Rock Laboratory were focussed mainly on the excavation disturbed zone (EDZ) in the tunnel driven by blasting and on the tunnel far-field. The analysis of in-situ-tests shows that the changes in the EDZ in the granite strongly depend on the local conditions. The permeability of the rock depends on the local properties of the rock and the presence of natural joints. The width of the EDZ is influenced by the excavation method. The width of the EDZ can be minimized by taking important factors into consideration during planning and construction. Permeability in the EDZ was examined using newly developed surface and short interval packers. The fluid flow in the zone occurs almost only in the fractures with permeability between k=10"-"1"7 m"2 and k=10"-"1"0 m"2. Although the permeability of individual fractures is relatively high, the permeability of the EDZ as a whole is low because the fractures have different permeabilities and lengths. The EDZ in the GRL is 30-50 cm wide. For simulation of the tests, computer programs based on the DURST programme system have been developed for two-phase flow and for 3-D gas-transport. (orig.)Available from TIB Hannover: F00B417+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung und Forschung (BMBF), Bonn (Germany); Bundesministerium fuer Wirtschaft, Bonn (Germany)DEGerman