Study on permeability evolution and damage mechanism along the EGS fracture in heat mining stage under thermal stress/cracking

Geothermal Energy

Science – Society – Technology

Table 2 Parameters related to damage model (Wei et al. 2015)

Parameters	Symbol	Value	Unit
Ultimate compressive strain coefficient	ηc	150	/
Ultimate tensile strain coefficient	ηt	5	/
Thermal expansion coefficient	α_T	6 × 10^–6	1/K
Internal friction angle	θ	45	°
Tensile strength	f_t	31	MPa
Compressive strength	f_c	280	MPa
Young’s modulus	E	39	GPa
Residual strength factor	λ	0.1	/
Specific heat capacity	C_m	950	J/kg/K