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Table 4 Fracture closure

From: Thermally driven fracture aperture variation in naturally fractured granites

Experiment \({P}_{\text{co}\_\text{r}}\) (MPa) \(T_\text{i}\) (\(^\circ\)C) \(T_\text{f}\) (\(^\circ\)C) \(\Delta\) t(h) \(b_\text{hi}\) (μm) \(b_\text{hf}\) (μm) \(\text{d}b_\text{hyd}/\text{d}t\) (10\(^{-11}\) m/s)
\(\#\)N14-S1 20 25 110 70 11.19 7.25 − 1.55
110 25 44 7.25 9.00 + 1.10
\(\#\)N14-S2 30 25 110 85 8.32 4.56 − 1.23
110 25 52 4.56 3.74 − 0.44
\(\#\)N14-S3 40 25 140 83 3.30 1.61 − 0.57
\(\#\)N19-C1 20 25 110 51 12.00 7.74 − 2.30
110 25 41 7.74 10.65 + 1.98
\(\#\)N19-C2 30 25 110 67 10.06 2.54 − 3.11
110 25 34 2.54 2.06 − 0.40
  1. Hydraulic measurements of hydraulic aperture (\(b_\text{hyd}\)), where \(T_\text{i}\) and \(T_\text{f}\) are the temperatures at the beginning and at the end of the respective cycle, \(\Delta\)t is the duration of the cycle, \(b_\text{hi}\) and \(b_\text{hf}\) are the hydraulic apertures at the beginning and at the end of the respective cycle, and \({P}_{\text{co}\_\text{r}}\) is the radial confining pressure