Bearing Capacity Factors
Nc
-
Nq
-
Nγ
-
Bearing Capacity Results
Ultimate Bearing Capacity
- kN/m²
Safe Bearing Capacity
- kN/m²
Detailed Calculation
Enter parameters and click Calculate to see detailed results.
Bearing Capacity Factors vs Friction Angle
Bearing Capacity vs Foundation Width
Terzaghi's Bearing Capacity Theory
Ultimate Bearing Capacity Formula
qu = cNc + qNq + 0.5γBNγ
Where:
- qu = Ultimate bearing capacity (kN/m² or psf)
- c = Soil cohesion (kPa or psf)
- q = Overburden pressure = γDf, where Df = depth of foundation
- γ = Unit weight of soil (kN/m³ or pcf)
- B = Width of foundation (m or ft)
- Nc, Nq, Nγ = Bearing capacity factors based on the soil's angle of internal friction (φ)
Safe Bearing Capacity
qsafe = qu / FoS
Where FoS is the Factor of Safety, typically ranging from 2.5 to 3.
Bearing Capacity Factors
The bearing capacity factors are calculated as:
- Nq = eπtanφ tan²(45 + φ/2)
- Nc = (Nq - 1) cotφ
- Nγ = 2(Nq + 1) tanφ