SPT Bearing Capacity Calculator
Allowable bearing for footings on sand straight from corrected SPT N-value.
On sands, SETTLEMENT governs long before shear failure โ these are settlement-limited values. N=20 medium sand โ 200 kPa; the field test IS the design chart.
Formula
SPT Bearing Capacity Calculator is a free spt n value bearing for geotechnical engineers and foundation designers โ instant, accurate and 100% client-side, with the governing formula and reference shown next to the result so the number can be defended, not just quoted.
About SPT Bearing Capacity Calculator
Allowable bearing for footings on sand straight from corrected SPT N-value. The calculation implements Meyerhof: q_a(25mm) = 12N (Bโค1.2m) ยท 8N((B+0.3)/B)ยฒ else; scale by settlement (Meyerhof (1956); Bowles foundation analysis). On sands, SETTLEMENT governs long before shear failure โ these are settlement-limited values. N=20 medium sand โ 200 kPa; the field test IS the design chart.
How to use SPT Bearing Capacity Calculator
- 1Enter Corrected SPT Nโโ.
- 2Enter Footing width in m.
- 3Enter Allowable settlement in mm.
- 4Read Allowable bearing (sand) instantly โ no submit button needed.
- 5Need US units? Flip the SI/Imperial toggle and every field converts.
Why use SPT Bearing Capacity Calculator?
- โImplements the standard formula โ Meyerhof: q_a(25mm) = 12N (Bโค1.2m) ยท 8N((B+0.3)/B)ยฒ else; scale by settlement
- โReference cited on-page: Meyerhof (1956); Bowles foundation analysis
- โOne-click SI โ Imperial toggle โ values convert in place, physics stays in SI
- โLive worked example: the substitution recomputes from your numbers
- โRuns entirely in your browser โ nothing uploaded, free forever
Frequently asked questions
What formula does the SPT Bearing Capacity Calculator use?+
It computes Meyerhof: q_a(25mm) = 12N (Bโค1.2m) ยท 8N((B+0.3)/B)ยฒ else; scale by settlement, per Meyerhof (1956); Bowles foundation analysis. The formula is displayed under the result along with a worked example substituted with your own inputs.
What should I keep in mind when using this calculator?+
On sands, SETTLEMENT governs long before shear failure โ these are settlement-limited values. N=20 medium sand โ 200 kPa; the field test IS the design chart.
Can this replace a soil investigation?+
No calculator replaces boreholes and lab tests โ but with investigated parameters in hand, this gives you the standard-method result instantly, with the formula shown so reviewers can check it.
Is the SPT Bearing Capacity Calculator free to use?+
Yes โ completely free, no sign-up, no limits. It runs client-side in your browser, so inputs stay private and results are instant even on slow connections.
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