Ground engineering · Groundwater & dewatering
Packer permeability test (Lugeon) calculator
Lugeon value of each stage using the effective pressure at the test section (gauge + water column − groundwater), and the representative value for the flow behaviour you choose.
Standard: Houlsby (1976) five-stage interpretation · 1 Lu = 1 L/min/m at 1 MPa ≈ 1.3 × 10⁻⁷ m/s
Open the live calculator → All ground engineering calculators
Inputs in the worked example
The live calculator starts with these values; change any of them and every result, check and diagram updates instantly.
| Input | Value | Unit |
|---|---|---|
| Test section length | 3 | m |
| Gauge height above ground | 1 | m |
| Depth to centre of test section | 20 | m |
| Depth to groundwater | 5 | m |
| Behaviour (from the pattern) | Laminar: average | |
| Target (e.g. dam curtain) | 5 | Lu |
| Stages: gauge pressure (kPa), flow (L/min) | 250, 4.1 420, 6.8 600, 9.8 420, 6.9 250, 4.2 |
Worked example — results
| Result | Value | Unit |
|---|---|---|
| Water column to section γw(hg + zm) | 206.0 | kPa |
| Groundwater pressure at section | 147.2 | kPa |
| Equivalent permeability (1 Lu ≈ 1.3 × 10⁻⁷ m/s) | 0.000 | m/s |
| Representative Lugeon value | 4.69 | Lu |
- ✓ Representative value ≤ target
Method, formulas and assumptions
- Water column to section γw(hg + zm) = 9.81*(1+20) = 206.01 kPa
- Groundwater pressure at section = 9.81*MAX(0,20-5) = 147.15 kPa
- Equivalent permeability (1 Lu ≈ 1.3 × 10⁻⁷ m/s) = CHOOSE(1,AVERAGE([t.lu]),INDEX([t.lu],3),MIN([t.lu]),INDEX([t.lu],5),INDEX([t.lu],5))*1.3E-7 = 6.098e-7 m/s
- Representative Lugeon value = CHOOSE(1,AVERAGE([t.lu]),INDEX([t.lu],3),MIN([t.lu]),INDEX([t.lu],5),INDEX([t.lu],5)) = 4.6905 Lu
- Friction losses in the pipework are ignored; deduct them for high flows or long rods.
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For preliminary design and education. Check every result against the current standard and your own engineering judgement before use.