Soil Bearing Capacity Calculator
Calculate ultimate and allowable soil bearing capacity using Terzaghi's equation. Inputs include soil cohesion, friction angle, and foundation geometry.
Inputs
Soft clay: 200–500 psf; stiff clay: 1,000–2,000 psf; hard clay: 2,000–4,000 psf
ASTM D3080: loose sand 28–32°; dense sand 36–40°; gravel 40–45°; clay 0–15°
Results
Ultimate Bearing Capacity
18,029 psf
Allowable Bearing (FS=3)
6,010 psf
How to Use This Calculator
- Enter soil cohesion (psf), friction angle (°), foundation width (B), foundation depth (D), and soil unit weight.
- Review Ultimate Bearing Capacity and Allowable Bearing Capacity (FS=3) in psf.
- Compare allowable bearing to your design footing pressure — reduce footing load or increase width if needed.
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