Ground engineering · Rock mechanics
Block sliding / toppling criteria calculator
Mode of a block of width b and height h on a plane of dip ψ with friction φ: stable, sliding, toppling or both.
Standard: Hoek & Bray block on an incline
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Inputs in the worked example
The live calculator starts with these values; change any of them and every result, check and diagram updates instantly.
| Input | Value | Unit |
|---|---|---|
| Block width | 1 | m |
| Block height | 3 | m |
| Plane dip ψ | 25 | ° |
| Friction angle φ | 35 | ° |
Worked example — results
| Result | Value | Unit |
|---|---|---|
| b/h | 0.333 | |
| tan ψ | 0.466 | |
| Slides (ψ > φ)? | no | |
| Topples (b/h < tan ψ)? | yes |
- ✓ No sliding
- ✗ No toppling
Method, formulas and assumptions
- b/h = 1/3 = 0.33333
- tan ψ = TAN(RADIANS(25)) = 0.46631
- Slides (ψ > φ)? = IF(25>35,"yes","no") = no
- Topples (b/h < tan ψ)? = IF(0.33333<0.46631,"yes","no") = yes
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For preliminary design and education. Check every result against the current standard and your own engineering judgement before use.