Crane Ground Bearing Pressure and Mat Size
Outrigger / crawler ground bearing pressure vs an allowable soil bearing, the area required to pass.
Example
You enter
- Worst-corner reaction (lb) 60000
- Float / pad / track contact area (ft²) 4
- Allowable soil bearing (psf) 3000
You get
- Ground bearing pressure 15000 psf
- Area required to pass 20 ft^2
- Square mat side 4.47 ft
Details, formula, and sources
Outrigger / crawler ground bearing pressure vs an allowable soil bearing, the area required to pass, and the square mat or cribbing side. A geotech source and a qualified person govern.
gbp = reaction / bearing_area; required_area = reaction / allowable; mat_side = sqrt(required_area); pass = gbp <= allowable.
OSHA 29 CFR 1926 Subpart CC and the manufacturer's outrigger-reaction chart by name; first-principles pressure = force / area.
OSHA 1926 Subpart CC is free at osha.gov. Allowable soil bearing comes from a geotechnical source.
Estimate. Head rigger and manufacturer working-load-limit charts govern. Inspect every piece of hardware before the show.
Field names used by the API: reaction_lb, bearing_area_ft2, allowable_psf, gbp_psf, required_ft2, mat_side_ft
- Pressure reaction divided by float / track contact areafirst-principles
- Mat size square mat side = sqrt(reaction / allowable)first-principles