Pipe Trench Excavation Earthwork
Trench excavation volume = average cross-section area × pipe length, for rainwater and sewage pipe layouts (pipe trench excavation).
| Manhole | Road level B | Road thick | Pipe invert C | Pipe dia D (mm) | Increment E | Base width G | Slope H | Excav. depth F | Cross area I | Pipe length K (m) | Avg cross area J | Earthwork L (m³) |
|---|
Total trench earthwork ΣL
—
m³
Excavation depth F = road level − road thickness − pipe invert + increment. Cross area I = (base width G + F·slope)·F. Average area J = (Iₘ + Iₘ₊₁)/2 between consecutive manholes; earthwork L = J·K (pipe length). Road thickness defaults to 0.7 m for rainwater and 0.7/0.75 for sewage and can be adjusted per row. Total = ΣL.