Infinite Slope Stability Calculator
Factor of safety of a long natural slope — dry or with seepage.
Full seepage roughly HALVES the frictional FS — a dry-stable 25° hillside fails in the monsoon. For cohesionless dry slopes the whole thing collapses to FS = tanφ/tanβ.
Formula
Infinite Slope Stability Calculator is a free infinite slope for geotechnical engineers and foundation designers — 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 Infinite Slope Stability Calculator
Factor of safety of a long natural slope — dry or with seepage. The calculation implements FS = [c′ + (γ−γ_w)z·cos²β·tanφ]/(γz·sinβ·cosβ) (Skempton & DeLory (1957); slope engineering). Full seepage roughly HALVES the frictional FS — a dry-stable 25° hillside fails in the monsoon. For cohesionless dry slopes the whole thing collapses to FS = tanφ/tanβ.
How to use Infinite Slope Stability Calculator
- 1Enter Slope angle β in °.
- 2Enter Soil friction angle φ in °.
- 3Enter Cohesion c′ in kPa.
- 4Enter Failure depth in m.
- 5Read Factor of safety instantly — no submit button needed.
Why use Infinite Slope Stability Calculator?
- ✓Implements the standard formula — FS = [c′ + (γ−γ_w)z·cos²β·tanφ]/(γz·sinβ·cosβ)
- ✓Reference cited on-page: Skempton & DeLory (1957); slope engineering
- ✓Built-in engineering verdict flags out-of-range results instantly
- ✓Runs entirely in your browser — nothing uploaded, free forever
Frequently asked questions
What formula does the Infinite Slope Stability Calculator use?+
It computes FS = [c′ + (γ−γ_w)z·cos²β·tanφ]/(γz·sinβ·cosβ), per Skempton & DeLory (1957); slope engineering. The formula is displayed under the result.
What should I keep in mind when using this calculator?+
Full seepage roughly HALVES the frictional FS — a dry-stable 25° hillside fails in the monsoon. For cohesionless dry slopes the whole thing collapses to FS = tanφ/tanβ.
Can this replace a soil investigation?+
No calculator replaces boreholes and lab tests — 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 Infinite Slope Stability Calculator free to use?+
Yes — 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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