Soil classification viewer (OSHA)
OSHA excavation soil types: what each is, the allowed slope, how to test and the mistakes that cause cave-ins.
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- Your own numbers, worked out as often as you like
- The full trench plan you can print or save to My work
- 5 cited sources, linked, with the checks to make
- Every other tool for the same role, in the same plan
- A plain-words read of your result (a fuller AI read with the Bifrost AI add-on)
Included in these role plans
Example result · fictional numbers
What you get: trench plan
Worked out by this tool from its default inputs. Its role plan lets you run your own numbers, print the sheet and save it.
Stable rock picked; design this 8.0 ft trench as Stable rock
- What it is
- Natural solid mineral matter that stays intact when excavated with vertical sides.
- Allowed slope (under 20 ft)
- Vertical sides allowed (0:1) when the rock is truly intact.
- Stability
- Highest; but seams and fractures downgrade it.
- How to test
- Visual inspection by a competent person, rock hammer.
- Common mistakes
- Treating fractured or weathered rock as stable; ignoring water seeping from seams.
Classification for this trench
- Soil picked
- Stable rock
- Conditions today
- Dry; nothing near the edge
- Design class
- Stable rock, as picked
- Maximum slope (under 20 ft)
- vertical (0:1)
- Benching
- Not needed in stable rock
Also on the sheet
- Protective system and digging · 4 lines, starting with “System”
- Access, spoil, air and water · 5 lines, starting with “Ladders or ramps”
- Daily inspection record · 4 lines, starting with “Inspected by (competent person)”
The plain-words read of this example
You picked Stable rock; with today's conditions (dry; nothing near the edge), design this trench as Stable rock. At 8.0 ft deep the competent person decides whether it needs protection. Set 4 ladders along the 200 ft so nobody travels more than 25 ft to get out. Keep spoil at least 2 ft back from the edge and inspect daily and after rain. Only the competent person on site can classify the soil, and the classification changes with the weather.
5 cited sources
- 29 CFR 1926 Subpart P, Appendix A: Soil classification (OSHA)
- 29 CFR 1926 Subpart P, Appendix B: Sloping and benching (Table B-1) (OSHA)
- 29 CFR 1926.652, Requirements for protective systems (OSHA)
- 29 CFR 1926.651, Specific excavation requirements (OSHA)
- 29 CFR 1926 Subpart P, Appendix F: Selection of protective systems (OSHA)
Plus 5 step-by-step checks, a print layout and a link that reopens it with your numbers.