Foundations · Pile testing & NDT
Static pile load test (Davisson) calculator
Load–settlement curve with the elastic line and Davisson offset to find the failure load.
Standard: Davisson (1972) offset limit · AS 2159 Section 8
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 |
|---|---|---|
| Pile length | 18 | m |
| Pile diameter / width | 450 | mm |
| Pile modulus | 32000 | MPa |
| Pile area (0 = circle from D) | 0 | mm² |
| Load (kN), settlement (mm) | 0, 0 500, 2.1 1000, 4.6 1500, 7.5 2000, 11.0 2400, 15.5 2700, 21.0 2900, 28.0 |
Worked example — results
| Result | Value | Unit |
|---|---|---|
| Elastic compression PL/AE | 3.537 | mm per 1000 kN |
| Offset 4 + D/120 | 7.75 | mm |
| Davisson limit load | 2,450 | kN |
| Settlement at limit | 16.4 | mm |
- ✓ Test reached the offset line
Method, formulas and assumptions
- Elastic line s = Q·L/(A·E)
- Offset line s = 4 mm + D/120 + Q·L/(A·E)
- Limit load where the measured curve crosses the offset line
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For preliminary design and education. Check every result against the current standard and your own engineering judgement before use.