Also in: Disaster Response and Recovery
Trench Spoil Pile Setback and Surcharge
Required spoil-pile setback (the larger of the OSHA 2 ft minimum and the depth-based surcharge), the pile toe spread.
Example
You enter
- Trench depth (ft) 10
- Spoil pile height (ft) 4
- Angle of repose (deg) 34
- Code minimum setback (ft) 2
You get
- Spoil pile toe spread 5.93 ft
- Governing setback 10
- Total clear from trench edge 15.93 ft
Checked against published worked examples from: OSHA 29 CFR 1926.651(j) / Subpart P.
Details, formula, and sources
ScopeRequired spoil-pile setback (the larger of the OSHA 2 ft minimum and the depth-based surcharge), the pile toe spread, and the total clear distance from the trench edge.
Formula or tablebase_halfwidth = spoil_height / tan(repose); setback = max(min_setback, trench_depth); total_clear = setback + base_halfwidth.
Source and editionOSHA 29 CFR 1926.651(j) (2 ft spoil setback) and Subpart P (protective systems) by name; first-principles geometry.
Free accessOSHA 1926 Subpart P is free at osha.gov. The 2 ft minimum is code text.
What governsEstimate. AHJ and licensed professional govern.
API field namestrench_depth_ft, spoil_height_ft, repose_deg, min_setback_ft, base_halfwidth_ft, setback_ft, total_clear_ft
- Code minimum 2 ft from the trench edge (OSHA 1926.651(j)(2))OSHA 29 CFR 1926.651(j)
- Angle of repose loose earth ~30-37 deg (default 34)soil mechanics