| 1. |
- Borgesson, L., et al.
(författare)
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Thermo-hydro-mechanical characterisation of a bentonite-based buffer material by laboratory tests and numerical back analyses
- 2001
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Ingår i: International Journal of Rock Mechanics And Mining Sciences. - 1365-1609 .- 1873-4545. ; 38:1, s. 95-104
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents some laboratory tests performed on the bentonite used as buffer material in the engineered barrier experiment in Kamaishi mine in Japan and a collective effort of four research groups to characterise the coupled thermo-hydro-mechanical behaviour of the bentonite by comparing numerical calculations with the laboratory test results. Each research group used finite element programs with constitutive models capable to simulate both liquid and vapour flux of water, heat transfer, volume change, swelling pressure and mechanical deformation. Numerical calibrations were performed against results obtained from three types of laboratory tests: water infiltration tests, thermal gradient tests and swelling pressure tests. Parameter values, which could not be directly measured in laboratory tests, were obtained with these calculations.
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| 2. |
- Nguyen, T. S., et al.
(författare)
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Hydro-mechanical response of a fractured granitic rock mass to excavation of a test pit - the Kamaishi Mine experiment in Japan
- 2001
-
Ingår i: International Journal of Rock Mechanics And Mining Sciences. - 1365-1609 .- 1873-4545. ; 38:1, s. 79-94
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Tidskriftsartikel (refereegranskat)abstract
- A thermo-hydro-mechanical experiment was conducted in a fractured granitic ruck mass at the Kamaishi Mine in Japan. The experiment consists of the excavation of a cylindrical test pit on the floor of an experimental drift. The test pit was then lilted with bentonite with an embedded heater. During the excavation of the test pit, the hydromechanical response of the surrounding rock was monitored. This paper presents the efforts of four research teams to numerically simulate the hydro-mechanical response of the rock mass during excavation. While the total inflow rate to the test pit, the flow distribution on the pit walls and the displacements in the rock mass away From the pit could be reasonably predicted, the pore pressure in individual boreholes, and the expansion behaviour of the pit were less successfully simulated. The reasons for these discrepancies are discussed in the paper.
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| 3. |
- Rutqvist, J., et al.
(författare)
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Coupled thermo-hydro-mechanical analysis of a heater test in fractured rock and bentonite at Kamaishi Mine - comparison of field results to predictions of four finite element codes
- 2001
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Ingår i: International Journal of Rock Mechanics And Mining Sciences. - 1365-1609 .- 1873-4545. ; 38:1, s. 129-142
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Tidskriftsartikel (refereegranskat)abstract
- Four computer codes were applied for a prediction of coupled thermo-hydro-mechanical responses during an in situ heater experiment which simulates a nuclear waste deposition hole with a waste over-pack and bentonite buffer, surrounded by fractured rock. The elevated temperature in the heater surroundings, which was maintained at 100 C for 8.5 months, generated substantial heat-driven moisture flow and swelling in the clay buffer, and thermal expansion of the surrounding fractured rock. Predicted system responses - including temperature. moisture content, fluid pressure, stress and displacement - were compared to measurements at 70 sensors located both in the clay buffer and the near-field rock. An overall good agreement between modeling and measured results indicates that most thermo-hydro-mechanical responses are fairly well represented by the coupled numerical models. Uncertainties occur for modeling of hydromechanical behavior of the swelling clay buffer at low saturation, modeling of near-field heterogeneous mechanical behavior of the low-stressed fractured reek, and modeling of the rock-buffer interface.
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| 4. |
- Rutqvist, J., et al.
(författare)
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Thermohydromechanics of partially saturated geological media : governing equations and formulation of four finite element models
- 2001
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Ingår i: International Journal of Rock Mechanics And Mining Sciences. - 1365-1609 .- 1873-4545. ; 38:1, s. 105-127
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents the general governing equations for coupled thermohydromechanical (THM) processes in saturated and unsaturated geologic formations and reviews four finite element codes fur modeling of such system. Three of the codes are developed for the special purpose of analyzing coupled THM processes in unsaturated porous and fractured geological media, and the fourth is a commercial code that has been used in its standard version, with a few adaptations for this specialized problem. The basic assumptions and fundamental equations for coupled THM processes in unsaturated porous fractured rock are presented. and formulations of the four finite element models are compared.
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