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Table 1 Friction and fracture parameters used in the simulations

From: Fluid pressure drops during stimulation of segmented faults in deep geothermal reservoirs

Parameter Description Value Source
E 0 Mechanical aperture 1200 µm Arbitrary (common values) (McClure 2012; Gischig 2015)
σ Enref Reference normal traction (mechanical aperture) 25 MPa
E res Residual mechanical aperture 2 µm
φ Edil Dilatation angle (mechanical aperture) 0°/2.5°/5° (Willis-Richards et al. 1996; Kohl and Mégel 2007)
e 0 Hydraulic aperture 120 µm Arbitrary (common values) (McClure 2012; Gischig 2015)
σ enref Reference normal traction (hydraulic aperture) 25 MPa
e res Residual hydraulic aperture 0.2 µm
φ Edil Dilatation angle (hydraulic aperture) 2.5° Arbitrary (good coupling)
ρ Fluid density 1000 kg/m3 Water values at 20 °C
µ Fluid viscosity 0.001 Pa s
h Out-of-plane dimension 100 m To obtain representative magnitudes
η Radiation damping coefficient 3 MPa/(m∕s) Arbitrary (common value) (McClure 2012)
S 0 Cohesion 0 MPa Assumption
G Shear modulus 15 GPa Arbitrary (common value)
ν r Poisson’s ratio 0.25 Arbitrary (common value)
f 0 Nominal friction coefficient 0.85 Arbitrary (common value) (Häring et al. 2008; Gischig 2015)
d c Characteristic displacement scale 100 µm Gouge material (Marone and Scholz 1988; Scholz 2002; Gischig 2015)
a Velocity effect coefficient 0.01 Scholz (2002)
b State effect coefficient 0.02
v 0 Reference velocity 10−6 m∕s Arbitrary (common value)
θ RS State 2.6·106 s Rubin and Ampuero (2005); Gischig (2015)
T str Matrix tension strength 3 MPa Arbitrary (common value)(McClure 2014)
K1crithf Stress intensity factor 1.5 MPa m1/2 Arbitrary (common value)(Zeeb and Konietzky 2015; Meyer et al. 2017)