Thermal-hydro-mechanical coupling damage model of brittle rock

LI Peng(李鹏), RAO Qiu-hua(饶秋华), LI Zhuo(李卓), MA Wen-bo(马雯波), MA Bin(马彬)

(School of Civil Engineering, Central South University, Changsha 410075, China)

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 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.

Key words:damage model; THM coupling mechanism; permeability test; THM coupling test; brittle rock