Overturning Safety Factor
Compute overturning safety factor FS from resisting and overturning moments.
Inputs
Formula
FS = Mresist / Moverturn
Usually FS≥1.5; seismic needs separate combination.
Fundamentals
Compute overturning safety factor FS from resisting and overturning moments.
This tool computes Overturning Safety Factor from the formula: FS = Mresist / Moverturn
History
Soil and structural mechanics were systematised in the 19th century, supporting modern civil design.
Engineering applications
Used for retaining, foundation and structural member design.
Glossary
| Resisting moment | Input parameter |
| Overturning moment | Input parameter |
| Overturn FS | Output result |
How to use
- Fill in Resisting moment, Overturning moment in the Inputs section (watch the unit on each field).
- Click Calculate; the tool evaluates the formula shown above.
- Read Overturn FS in the results area.
Formula · Worked Example · Knowledge
Formula
核心计算关系：FS = Mresist / Moverturn
输入变量：
- Resisting moment
Mresist— kN·m - Overturning moment
Moverturn— kN·m
输出结果：
- Overturn FS
FS
假设/适用：Earth pressure uses Rankine/Coulomb active assumptions; passive & surcharge handled separately.
Worked Example
根据公式 FS = Mresist / Moverturn，取 Resisting moment = 500 kN·m；Overturning moment = 200 kN·m。
代入计算得：Overturn FS = 2.5。
Key Points
- Earth pressure uses Rankine/Coulomb active assumptions; passive & surcharge handled separately.
- Check both strength and stability (overturning, sliding).
- Support reactions from static equilibrium; continuous structures need force/displacement method.
Parameters
Inputs
| Parameter | Symbol | Unit | Default |
|---|---|---|---|
| Resisting moment (kN·m) | Mresist | kN·m | 500 |
| Overturning moment (kN·m) | Moverturn | kN·m | 200 |
Outputs
| Result | Symbol | Unit |
|---|---|---|
| Overturn FS | FS |
Applications
- Simply-supported/cantilever reactions
- Structural equilibrium analysis
- Shear & moment distribution
FAQ
What formula does this tool use?
This tool computes per ISO / AGMA / ASME standard formulas: FS = Mresist / Moverturn
How accurate are the results?
Results match input precision, based on SI units and common engineering approximations; for critical duty re-check with a safety factor.
Where is it used?
Simply-supported/cantilever reactions