Slope Stability Calculator
Calculate the factor of safety for a slope using simplified limit equilibrium analysis.
How to Use the Slope Stability Calculator
- Enter the slope height in metres.
- Enter the slope angle in degrees.
- Enter soil cohesion in kPa and friction angle in degrees.
- Enter the unit weight and click Calculate.
Cas d'utilisation
- •Assessing embankment and cutting stability.
- •Geotechnical investigation support.
- •Landslide risk assessment.
- •Retaining wall backfill slope evaluation.
Formule
FOS = (c'L + N·tan φ') / (W·sin α), where N = W·cos α, L = H/sin α.
Questions fréquemment posées
What factor of safety is acceptable?
FOS ≥ 1.5 is generally considered safe; 1.0–1.5 is marginal; below 1.0 the slope is unstable.
What is cohesion?
Cohesion c' is the component of shear strength independent of normal stress, present in clay and silt soils.
Is it free?
Yes, all calculators on OhMyCalc are completely free.