Analyses of coupled hydrological-mechanical effects during drilling of the FEBEX tunnel at Grimsel
This paper presents analyses of coupled hydrological-mechanical (HM) processes during drilling of the FEBEX tunnel, located in fractured granite at Grimsel, Switzerland. Two and three-dimensional transient finite-element simulations were performed to investigate HM-induced fluid-pressure pulses, observed in the vicinity of the FEBEX tunnel during its excavation in 1995. The results show that fluid-pressure responses observed in the rock mass during TBM drilling of the FEBEX tunnel could not be captured using current estimates of regional stress. It was also shown that the measured pressure responses can be captured in both two and three-dimensional simulations if the stress field is rotated such that contraction (compressive strain rate) and corresponding increases in mean stress occur on the side of the drift, where increased fluid pressure spikes were observed.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- Swedish Nuclear Power Inspectorate (SKI) Grant 50062 (US)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 816789
- Report Number(s):
- LBNL-53752; R&D Project: 843801; TRN: US200321%%199
- Resource Relation:
- Conference: GEOPROC 2003, Stockholm (SE), 10/13/2003--10/15/2003; Other Information: PBD: 2 Sep 2003
- Country of Publication:
- United States
- Language:
- English
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