Concrete · Special elements
Concrete bearing stress calculator
Bearing capacity under a plate with the √(A2/A1) enhancement capped at 2.0.
Standard: AS 3600 Cl 12.6
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 |
|---|---|---|
| Bearing load N* | 1200 | kN |
| Plate length | 300 | mm |
| Plate width | 300 | mm |
| Supporting area length (geometric similar) | 600 | mm |
| Supporting area width | 600 | mm |
| f′c | N32 | MPa |
Worked example — results
| Result | Value | Unit |
|---|---|---|
| A1 | 90,000 | mm² |
| A2 | 360,000 | mm² |
| √(A2/A1) ≤ 2 | 2.00 | |
| φNb = 0.6·0.9 f′c A1 √(A2/A1) | 3,110 | kN |
- ✓ N* ≤ φNb
Method, formulas and assumptions
- A1 = 300*300 = 90000 mm²
- A2 = 600*600 = 3.600e+5 mm²
- √(A2/A1) ≤ 2 = MIN(2,SQRT(3.600e+5/90000)) = 2
- φNb = 0.6·0.9 f′c A1 √(A2/A1) = 0.6*0.9*32*90000*2/1000 = 3110.4 kN
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For preliminary design and education. Check every result against the current standard and your own engineering judgement before use.