Thermal-hydro-mechanical coupling damage model of brittle rock

Abstract

Based on fluid mechanics, thermodynamics and damage mechanics, thermal-hydro-mechanical (THM) coupling damage model of brittle rock is established by analyzing THM coupling mechanism, where THM coupling damage variable D_THM is dominated by TH coupling damage variable D_TH, TM coupling damage variable D_TM and HM coupling damage variable D_HM, and D_TH is firstly expressed in term of dimensionless total thermal conductivity of the water Nu. Permeability test, uni-axial compression test and THM coupling test are conducted to measure the permeability, elastic modulus and THM coupling stress-strain curves of brittle rock. The tested values of THM coupling elastic modulus E_THM′ are in good agreement with the predicted values of THM coupling elastic modulus E_THM, which can verify the newly established THM coupling damage model.

Keywords

damage model / THM coupling mechanism / permeability test / THM coupling test / brittle rock

References

[1] JingL, TsangC F, StephanssonO. DECOVLALEX: An international co-operative research project on mathematical models of coupled THM processes for safety analysis of radioactive waste repositories [J]. International Journal of Rock Mechanics and Mining Sciences, 1995, 32(5): 389-398

[2] HudsonJ A, StephanssonO, AnderssonJ, TsangC F, JingL. Coupled T-H-M issues relating to radioactive waste repository design and performance [J]. International Journal of Rock Mechanics & Mining Sciences, 2001, 38(1): 143-161

[3] RutqvistJ, ChijimatsuM, JingL, MillardA, NguyenT S, RejebA, SugitaY, TsangC F. A numerical study of THM effects on the near-field safety of a hypothetical nuclear waste repository-BMT1 of the DECOVALEX III project. Part 3: Effects of THM coupling in sparsely fractured rocks [J]. International Journal of Rock Mechanics and Mining Sciences, 2005, 42(5/6): 745-755

[4] RaoQ-h, XieH-f, XieQiang. In-plane shear(Mode II)crack sub-critical propagation of rock at high temperature [J]. Journal of Central South University of Technology, 2008, 15s1: 402-405

[5] NowakT, KunzH, DixonD, WangW-q, GorkeU, KolditzO. Coupled 3-D thermo-hydro-mechanical analysis of geotechnological in situ tests [J]. International Journal of Rock Mechanics & Mining Sciences, 2011, 48(1): 1-15

[6] ChenY-f, LiD-q, JiangQ-h, ZhouC-bing. Micromechanical analysis of anisotropic damage and its influence on effective thermal conductivity in brittle rocks [J]. International Journal of Rock Mechanical and Mining Sciences, 2012, 50: 102-116

[7] LiuQ-s, XuX-chang. Damage analysis of brittle rock at high temperature [J]. Chinese Journal of Rock Mechanics and Engineering, 2000, 19(4): 408-411

[8] BlahetaR, ByczanskiP, CermarkM, HrtusR, KohutR, KolcunA, MalikJ, SysalaS. Analysis of aspo pillar stability experiment: Continuous thermo-mechanical model development and calibration [J]. Geotechnical Engineering, 2013, 5(2): 124-135

[9] ChenY-f, ZhouC-b, JingL. Numerical modeling of coupled thermo-mechanical response of a rock pillar [J]. Journal of Rock Mechanics and Geotechnical Engineering, 2010, 2(3): 262-273

[10] FerdinandoM, ReneC, YannickS. Two scale model for hydro-mechanical damage model [J]. Energies Nouvelles, 2011

[11] ZhaoW-c, WangT-t, JuG-s, ZhengD-chun. The study on fractal damage of rock under hydraulic fracturing basing on conversation of energy [J]. Applied Mechanics and Materials, 2010, 29/30/31/32: 1363-1368

[12] VychytilJ, HoriiH. Micromechanics-based continuum model for hydraulic fracturing of jointed rock masses during HDR stimulation [J]. Mechanics of Materials, 1998, 28(1/2/3/4): 123-135

[13] KwonS, ChoW J. The influence of an excavation damaged zone on the thermal-mechanical and hydro-mechanical behaviors of an underground excavation [J]. Engineering Geology, 2008, 101(3/4): 110-123

[14] ThomasH R, CleallP J. Inclusion of expansive clay behaviour in coupled thermo hydraulic mechanical models [J]. Engineering Geology, 1999, 54(1/2): 93-108

[15] FuguoT, LanruJ, RobertW Z. An effective thermal conductivity model of geological porous media for coupled thermohydro-mechanical systems with multiphase flow [J]. International Journal of Rock Mechanics and Mining Sciences, 2009, 46(8): 1358-1369

[16] ZhaoJian. Experimental study of flowrock heat transfer in rock fracture [J]. Chinese Journal of Rock Mechanics and Engineering, 1999, 18(2): 119-123