Site Evaluation, Setup, and Ground Conditions
What this domain tests
This domain tests the pre-setup survey: can you find a position where the carrier, outriggers, and spoil pile are stable, legal, and clear of overhead and underground hazards?
Core rules
- Call 811 and locate underground utilities, septic tanks, culverts, and old foundations before any auger touches soil.
- Evaluate soil type, compaction, voids, frost, water, and slope. Native compacted soil is preferred; backfill, trench edges, and manhole covers are not outrigger support unless engineered.
- Keep outriggers fully extended with pads or cribbing that spread load. Chock wheels, set parking brake, and engage PTO per manufacturer procedure.
- Locate the truck so the boom and load stay clear of energized lines, trees, and traffic; establish an exclusion zone and a spoil area away from the hole edge.
Ground bearing worked example
An outrigger float is 24 in x 24 in = 576 in2 and carries 12,000 lb. Pressure = 12,000 / 576 = 20.8 psi, or about 3,000 psf. If the soil is rated at 2,000 psf, the float is too small. Required area = 12,000 / 2,000 = 6 ft2 (864 in2); a 30 in x 30 in pad provides 900 in2, so it works. This reasoning, not a guess, is what the exam rewards.
Traps
Assuming outriggers compensate for slope; setting on fresh backfill because it “looks solid”; ignoring the spoil pile surcharge near the hole; and failing to check overhead lines before raising the boom.
Key points
- Call 811 and verify marks before digging.
- Use pads sized from load and soil bearing pressure.
- Never set outriggers on backfill, voids, or covers.
- Keep the machine level and all outriggers in contact.
- Plan exclusion zone and spoil location before setup.