Planning & Estimating Earthwork
Planning and estimating is where a C-12 job is won or lost: you read the plans, size up the dirt, and figure out whether the site balances.
Cut, fill, and balancing
Cut is removing material from areas above the design grade; fill is placing and compacting material where the ground is below grade. A grading plan is balanced when the volume of cut equals the volume of fill — the ideal, because you neither import nor export dirt.
Key ideas: balanced = cut volume equals fill volume · swell = loose volume > bank volume (excavated soil bulks) · shrinkage = compacted fill < bank volume · percent grade = (rise ÷ run) × 100.
When a site needs more fill than the cut produces, you import (borrow) material; when there’s a surplus, you export it. Shrink and swell factors let you convert between bank, loose, and compacted volumes to estimate haul quantities accurately.
Reading plans and laying out the job
Estimating starts with the plans and specifications and the job-site conditions — soil type, groundwater, and access all change the number. Once the job is awarded, project layout (staking) transfers line and grade from the plans to the ground so the crew cuts and fills to the right elevations.
Practice: Planning & Estimating Earthwork
Frequently asked
What does it mean to balance a grading site?
How do you calculate percent grade?
What is the difference between shrinkage and swell?
More C-12 Earthwork & Paving topics
Soils & Compaction
C-12 study guide on soils and compaction: the Proctor test, maximum dry density, optimum moisture content, relative compaction, standard vs modified Proctor, and lifts.
Read & practice →Excavation & Grading
C-12 study guide on excavation and grading: the pavement structure (subgrade, subbase, base course), load distribution, benching fill into slopes, grade control, and trench backfill.
Read & practice →Paving & ADA
C-12 study guide on paving: asphalt vs concrete pavement, prime and tack coats, base failure causes, concrete joints, and ADA slope limits for ramps, parking, and cross slope.
Read & practice →Excavation Safety (OSHA)
C-12 study guide on OSHA trench and excavation safety: when a protective system is required, soil types and slopes, the competent person, access and egress, spoil placement, water, and atmospheres.
Read & practice →Stormwater & Environmental
C-12 study guide on construction stormwater: when a site needs Construction General Permit coverage, the SWPPP and QSD/QSP roles, and erosion control vs sediment control BMPs.
Read & practice →Work-Zone Traffic Control
C-12 study guide on work-zone traffic control for paving and roadway jobs: orange signs, taper length, the flagger's STOP/SLOW paddle, and channelizing device spacing.
Read & practice →