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DECOVALEX-2011 Task A – Step 1 JAEA’s Results. Japan Atomic Energy Agency Shigeo Nakama and Tomoo Fujita. DECOVALEX-2011 3 rd Workshop in Korea 2009/04. Contents. Simulation flow Summary of Step 0 on JAEA team Model description and input data on Step 1 Simulation results on Step 1
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DECOVALEX-2011 Task A – Step 1JAEA’s Results Japan Atomic Energy Agency Shigeo Nakama and Tomoo Fujita DECOVALEX-2011 3rd Workshop in Korea 2009/04
Contents • Simulation flow • Summary of Step 0 on JAEA team • Model description and input data on Step 1 • Simulation results on Step 1 (including compare with in-situ data) • Conclusions
Simulation flow Step1~ Step0 Simulation of Ventilation Experiment (Phase 1) Simulation of Drying Test Properties of Opalinus Clay Today’s Presentation Water retention curve parameter of relative permeability
Summary of Step 0 on JAEA team Solid grain density • Properties of Opalinus Clay Porosity andsaturated volumetric water content Void ratio Permeability • Water retention curve (modified Van Genuchten model) • parameter of relative permeability l=0.65
Simulation model for Step1 σ=3.2MPa, pw=1.21MPa pw=1.21MPa σ=3.2MPa Micro tunnel(φ=1.3m) 130m Opalinus Clay pw=2.49MPa σ=6.6MPa 130m From DECOVALEX-2011: Description of Task A
Simulation model (mesh) for Step1 • Node: 3960 65m • Element: 1888 130m 1.3m
Applied Relative humidity Step 1 P2 Phase 0 P1
Suction of microtunnel wall • Kelvin law No.2 No.1 No.3 No.4 Applied RH No.5
Compare simulation with VE 100 80
Water pressure (simulation results) n3187 n3003 n1185 n1311 n1087 n773
Water pressure (simulation and in-situ data) n3187 n3003 In-situ data n1185 n1311 n1087 n773
Water pressure (in-situ data) n3187 n3003 n1185 n1311 n1087 n773
Distribution of water pressure Unsaturated zone vertical 45degree Micro tunnel horizontal Gap (0.6m)
Relative displacement around the micro tunnel (simulation and in-situ data) sidewall compression (BVE-47) (BVE-49) expansion
Relative displacement around the micro tunnel (simulation and in-situ data) sidewall (BVE-47) compression (BVE-49) expansion
Deformation mechanism • Effective stress principle for porous media : Total stress : Effective stress : Saturation (Sr) Effective stress Water pressure : wetting liquid pressure decrease increase : Unit matrix expansion 85%=>100% increase decrease (suction) compression 100%=>80%=>30%=>2%
Relative displacement around the micro tunnel (simulation and in-situ data) Gap sidewall (BVE-47) compression (BVE-49) expansion Gap
Effect of volumetric swelling thermal expansion • Effective strain saturation driven moisture swelling volume change ratio by entrapment of liquid elastic pore pressure Model-1 c.f. buffer material of Japanese H12 design Model-2 Model-3 Advised by Dr. Garitte
Relative displacement around the microtunnel (considered moisture swelling)
Relative displacement around the micro tunnel (considered moisture swelling) roof (BVE-46) sidewall (BVE-47, 49) batholith (BVE-48) sidewall Gap roof batholith Gap Gap Gap Gap Gap
Effect of volumetric swelling with anisotropy Model-2 Horizontal direction Vertical direction
Relative displacement around the micro tunnel (moisture swelling with anisotropy) roof (BVE-46) sidewall (BVE-47, 49) batholith (BVE-48) sidewall Influence of adapted RH on micro tunnel wall roof batholith other mechanism?
Conclusions (1) • Relative humidity • Water pressure • Good agreement between results of simulation and Ventilation Experiment data. => Setting parameter, assumption and model are reasonable. => Small difference (location, unsaturated zone) was considered as the cause by boundary condition of micro tunnel wall. Because we adapted “RH-in” data directory, but in fact, there was difference between “RH-in” and “RH tunnel sensor”.
Conclusions (2) • Relative displacement around tunnel • Simulation denote the same tendency of VE data => basal deformation mechanism is effect of water pressure (suction) • Magnitude of displacement is a difference between simulation and in-situ data. => We considered that moisture swelling is included in displacement data. => There is anisotropy in moisture swelling. • We can not simulate displacement of roof of micro tunnel. => There is other displacement mechanism. • Water balance =>We will estimate after the workshop. Sorry.