Glossary • Earthwork
Cut / Fill Volume Calculation
Cut = excavation (BCY). Fill = embankment (CCY). Balance = cut − fill. Get it right before bid day — or pay for haul you didn't price.
DTM Method (how BidSync does it)
- Existing DTM + Proposed DTM from contours, spot elevations, breaklines (automated detection, no digitizer).
- Stripping / subsidence / over-excavation adjusted per depth.
- Per-stratum swell/shrink (common earth 20%/10%, clay 30%/15% — from geotech).
- BCY cut → LCY haul → CCY fill balance sheet pushed to heavy-civil assemblies with Plan/Spec evidence.
Manual check
(Area × Avg Depth)/27 = CY + stripping (Area × in/12)/27. Use the earthwork calculator for quick math.
Common traps
- Ignoring 4" stripping over large footprint
- One global shrink factor for mixed strata
- Balancing BCY vs LCY (mixing units)
How BidSync handles it
Upload PDF/DWG → DTM diff → 3-column balance (BCY/LCY/CCY) → bid items — every yard traced to sheet/contour log for DOT audit.
FAQ
How to calculate cut and fill automatically?
DTM from plans → auto BCY/CCY balance to bid. Manual: (Area×Depth)/27 + stripping.
What is DTM?
Digital Terrain Model — 3D surface from contours/spots/breaklines; diff existing vs proposed.