地基承载力计算器 — 公式
## Terzaghi's Bearing Capacity Theory
The bearing capacity of a shallow foundation depends on soil properties, foundation depth, and width.
### Formula (strip footing)
**q_u = c Nc + gamma Df Nq + 0.5 gamma B Ngamma**
The three terms represent cohesion resistance, surcharge (overburden) resistance, and self-weight resistance. Nc, Nq, and Ngamma are dimensionless bearing capacity factors that depend on the soil friction angle.
The bearing capacity of a shallow foundation depends on soil properties, foundation depth, and width.
### Formula (strip footing)
**q_u = c Nc + gamma Df Nq + 0.5 gamma B Ngamma**
The three terms represent cohesion resistance, surcharge (overburden) resistance, and self-weight resistance. Nc, Nq, and Ngamma are dimensionless bearing capacity factors that depend on the soil friction angle.
计算示例
A 2 m wide strip footing at 1.5 m depth, c=20 kPa, gamma=18 kN/m^3, phi=20 deg.
- Cohesion term: 20 x 17.7 = 354 kPa
- Surcharge term: 18 x 1.5 x 7.4 = 199.8 kPa
- Width term: 0.5 x 18 x 2 x 5.0 = 90 kPa
- q_u = 354 + 199.8 + 90 = 643.8 kPa
- q_a = 643.8 / 3 = 214.6 kPa (with FoS = 3)