Also in: Disaster Response and Recovery
OSHA Trench Sloping
Maximum slope ratio per soil class A/B/C and benching geometry.
Example
You enter
- Trench depth (ft) 8
- Soil class B
- Surcharge near trench false
You get
- Setback per side 8.00 ft
- Top width (2 ft floor) 18.00
- Bench height 4.0 ft
Checked against published worked examples from: OSHA.
Details, formula, and sources
Formula or tableMaximum allowable slope ratio (H:V) per OSHA 29 CFR 1926.652 and Appendix B: Type A 0.75:1, Type B 1:1, Type C 1.5:1. Benching geometry per Appendix B Figure B-1.1.
Source and editionOSHA 29 CFR 1926 Subpart P and Appendix B by section.
Free accessFree at ecfr.gov.
What governsEstimate. AHJ and licensed structural engineer govern.
API field namesdepth_ft, soil_class, surcharge, max_horizontal_ft, top_width_ft, bench_height_ft
- Soil-class table data/crosswalks/osha-trench.json29 CFR 1926 Appendix B