Civil Earthworks Progress Survey | Cut/Fill, Volumes & CAD Surfaces | Project

Georeferenced drone orthomosaic of an active civil earthworks site across two construction stages — Site orthomosaic — active earthworks across two construction stages, GDA2020 / MGA Zone 55.

Measuring an active earthworks site without stopping it

Civil earthworks move daily. Progress claims, fill forecasts and programme decisions all depend on knowing what the ground actually looks like right now — and a conventional ground survey of an 18-hectare active site is slow, costs machine downtime and still leaves gaps between pickup points.

A single drone mobilisation captures the whole site in one pass, at a density no ground survey matches economically, and produces a surface that imports directly into the contractor's civil software. This survey was commissioned across two stages of the subdivision while earthworks were still running.

Project typeProgress survey

Earthworks against design, mid-construction

LocationGeelong region

Victoria

Survey area18.6 ha

Captured in a single mobilisation

Ground resolution0.9 cm

Average GSD · GDA2020 / MGA55 + AHD

Capture & QA

A reconstruction you can put a number against.

Capture flown with a DJI Zenmuse P1 (35 mm) and processed in-house through PIX4Dmatic. Every survey is issued with its QA record, because a surface without an accuracy statement isn't a survey — it's a picture.

Images calibrated2,790

100% — single connected block

Dense point cloud385.6M

points across the survey area

Median image matches12,534

per calibrated image — strong connectivity

GCP mean RMS0.016 m

position error against ground control

Coordinate framework

All outputs are delivered in GDA2020 / MGA Zone 55 with AHD heights via AUSGeoid2020 (EPSG:7855 + 5711). Camera-internal optimisation shifted by only 0.05% during processing, indicating a stable calibration solution. The 1 m LandXML surface was validated by an automated QA check against the source raster before issue.

Deliverables

What the client received.

Digital orthomosaic (GeoTIFF) at 2.0 cm/px
Digital surface model (GeoTIFF) at 2.0 cm/px
1 m LandXML TIN surface for TBC / civil software import
Automated QA validation record for the LandXML surface
0.25 m 3D contours (DXF) with QGIS layer style
Current-versus-design difference rasters, Final Surface and Bulk Earthworks
Cut/fill quantity summary (CSV)
Stockpile volume report — 3 polygons
Civil Earthworks Progress Survey Report with Pix4D quality report appended

Cut and fill against design

Colour-classified cut and fill difference plan comparing the surveyed current surface against the Final Surface design — Final Surface difference plan — where the site sits above and below design. Positive values indicate fill required; negative values indicate cut required.

Stockpile volumes

Stockpiles across the site were measured directly against the point cloud rather than paced out or estimated from a load count. Volumes are the fastest payback on a progress survey — they take minutes to pull from a dataset that has already been captured, and they turn an argument into a number everyone can see on the same plan.

Current versus design

The surveyed surface was compared against both the Final Surface and Bulk Earthworks designs, producing a colour-classified plan of where the site sits above and below design and how much material still has to move to get there. Mid-programme that answers the questions actually driving decisions — which areas are close to finished, where the remaining fill is concentrated, and whether the earthworks budget still looks right.

Repeatable by design

Every output is georeferenced to a single coordinate framework and archived against the survey date. A repeat flight at any future interval drops onto the same framework, so month-on-month earthworks movement, fill placement and stockpile drawdown can be measured against this survey rather than estimated between them.

Quantities and surfaces described here are derived from remote-sensing data and are indicative unless independently verified against survey control. The current surface is a photogrammetry DSM and above-ground objects are not excluded.

Civil earthworks — progress survey for an active subdivision site.