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Results of simulations using the lattice-Boltzmann method_
| Sample no. | Sample name | VOI size | Porosity derived from image data | Permeability | Hydraulic conductivity at 10°C |
|---|---|---|---|---|---|
| [vx] | φimg [−] | k [μm2] | K [m/s] | ||
| 1 | Fine sand | 4003 | 0.365 | 23.489 | 1.758E-4 |
| 6003 | 0.364 | 17.567 | 1.317E-4 | ||
| 2 | Fine sand with lignite | 4003 | 0.511 | 20.923 | 1.565E-4 |
| 6003 | 0.511 | 23.193 | 1.736E-4 | ||
| 3 | Medium sand | 4003 | 0.309 | 16.778 | 1.259E-4 |
| 6003 | 0.317 | 15.396 | 1.151E-4 | ||
Results of measurements with the described small-scale permeameter setup_
| Sample no. | Sample name | Mean conductivity derived from the best-fit curve | Conductivity of the apparatus | Hydraulic conductivity in the measurement temperature | Hydraulic conductivity at 10°C |
|---|---|---|---|---|---|
| Kequiv [m/s] | Kap [m/s] | Kex [m/s] | Kcorr [m/s] | ||
| 1 | Fine sand | 2.663E-5 | 4.927E-3 | 2.678E-5 | 1.951E-5 |
| 2 | Fine sand with lignite | 4.457E-6 | 4.461E-6 | 3.250E-6 | |
| 3 | Medium sand | 6.183E-5 | 6.262E-5 | 4.562E-5 | |
Results of simulations using the pore-network modeling approach_
| Sample no. | Sample name | VOI size | Porosity derived from image data | Permeability | Hydraulic conductivity at 10°C |
|---|---|---|---|---|---|
| [vx] | φimg [−] | k [μm2] | K [m/s] | ||
| 1 | Fine sand | 4003 | 0.365 | 23.666 | 1.786E-4 |
| 6003 | 0.364 | 23.587 | 1.780E-4 | ||
| 8003 | 0.363 | 24.061 | 1.816E-4 | ||
| 2 | Fine sand with lignite | 4003 | 0.511 | 28.433 | 2.145E-4 |
| 6003 | 0.511 | 27.969 | 2.110E-4 | ||
| 8003 | 0.506 | 27.338 | 2.063E-4 | ||
| 3 | Medium sand | 4003 | 0.309 | 17.311 | 1.306E-4 |
| 6003 | 0.317 | 20.301 | 1.532E-4 | ||
| 8003 | 0.317 | 22.087 | 1.667E-4 | ||
Measured properties of the samples_
| Sample no. | Sample name | Soil type according to PN-EN ISO 14688-2:2018 | Bulk density | Specific density | Porosity in loose state | Hydraulic conductivity in falling-head test at 10°C | Uniformity coefficient U=d60/d10 | GSD curve slope coefficient C=d302/(d60·d10) |
|---|---|---|---|---|---|---|---|---|
| [−] | ρ [g/cm3] | ρs [g/cm3] | φ [−] | K [m/s] | U [−] | C [−] | ||
| 1 | Fine sand | FSa | 1.549 | 2.634 | 0.412 | 1.702E-5 | 1.840 | 1.054 |
| 2 | Fine sand with lignite | FSa | 1.238 | 2.644 | 0.532 | 3.189E-6 | 2.532 | 1.027 |
| 3 | Medium sand | MSa | 1.652 | 2.654 | 0.377 | 4.067E-5 | 3.147 | 1.003 |
Results of estimation using the Kozeny–Carman equation_
| Sample no. | Sample name | VOI size | Porosity derived from image data | Tortuosity in direction of the flow | Specific surface area per unit volume | Permeability | Hydraulic conductivity at 10°C |
|---|---|---|---|---|---|---|---|
| [vx] | φimg [−] | τ [−] | S [1/m] | k [μm2] | K [m/s] | ||
| 1 | Fine sand | 4003 | 0.365 | 1.937 | 38748 | 16.587 | 1.242E-4 |
| 6003 | 0.364 | 1.935 | 38447 | 16.674 | 1.249E-4 | ||
| 8003 | 0.363 | 1.897 | 37820 | 17.378 | 1.301E-4 | ||
| 2 | Fine sand with lignite | 4003 | 0.511 | 1.732 | 72321 | 24.639 | 1.845E-4 |
| 6003 | 0.511 | 1.722 | 73061 | 24.283 | 1.818E-4 | ||
| 8003 | 0.506 | 1.763 | 72932 | 22.645 | 1.696E-4 | ||
| 3 | Medium sand | 4003 | 0.309 | 2.009 | 40988 | 7.323 | 5.484E-4 |
| 6003 | 0.317 | 1.980 | 40043 | 8.604 | 6.443E-4 | ||
| 8003 | 0.317 | 1.946 | 37079 | 10.209 | 7.645E-4 | ||
Summary of used empirical formulae_
| Method | Equation form | Coefficient C or C′ | Porosity function f(φ) | Effective diameter de | Exponent m | Applicability |
|---|---|---|---|---|---|---|
| Seelheim (1880) | (5) | 3570 | 1 | d50 | 2 | Sands and clays |
| Hazen (1911) | (4) | 6.0E-4 | 1+10(φ−0.26) | d10 | 2 | 0.1 mm<d10<3 mm* |
| U<5 | ||||||
| Sauerbrey (1932) | (4) | 3.75E-3 | φ3/(1−φ)2 | d17 | 2 | d17<5 mm |
| USBR (Říha et al., 2018) | (4) | 4.8E-4·(1000d20)0.3 | 1 | d20 | 2 | U<5 |
| Beyer (1964) | (4) | 6E-4·log(500/U) | 1 | d10 | 2 | 0.06 mm<d10<0.6 mm |
| 1<U<20 | ||||||
| Chapuis et al. (2005) | (5) | 1219.9 | φ2.3475/(1−φ)1.565 | d10 | 1.565 | 0.03 mm<d10<3 mm |
Results of estimation using empirical equations_
| Sample no. | Sample name | Method | Effective diameter | Effective diameter value | Hydraulic conductivity at 10°C |
|---|---|---|---|---|---|
| [−] | [−] | de [mm] | K [m/s] | ||
| 1 | Fine sand | Seelheim | d50 | 0.273 | 2.661E-4 |
| Hazen | d10 | 0.163 | 3.031E-4 | ||
| Sauerbrey | d17 | 0.189 | 2.045E-4 | ||
| USBR | d20 | 0.201 | 8.937E-5 | ||
| Beyer | d10 | 0.163 | 2.927E-4 | ||
| Chapuis | d10 | 0.163 | 4.125E-4 | ||
| 2 | Fine sand with lignite | Seelheim | d50 | 0.138 | 6.799E-5 |
| Hazen | d10 | 0.062 | N/A | ||
| Sauerbrey | d17 | 0.077 | 1.151E-4 | ||
| USBR | d20 | 0.082 | 1.150E-5 | ||
| Beyer | d10 | 0.062 | 3.994E-5 | ||
| Chapuis | d10 | 0.062 | 2.363E-4 | ||
| 3 | Medium sand | Seelheim | d50 | 0.381 | 5.182E-4 |
| Hazen | d10 | 0.143 | 2.01E-4 | ||
| Sauerbrey | d17 | 0.179 | 1.254E-4 | ||
| USBR | d20 | 0.196 | 8.531E-5 | ||
| Beyer | d10 | 0.143 | 2.037E-4 | ||
| Chapuis | d10 | 0.143 | 2.496E-4 | ||