A case study application of unmanned aerial systems (UAS) on highway construction projects

Earthwork operations are often one of the major cost items on infrastructure construction projects. Precise estimates of actual earthwork volumes are important for both transportation agencies and contractors alike to ensure appropriate payments are made. Recently, unmanned aerial systems (UAS) have become popular for numerous surveying applications because they require less cost and time consumption compared with other common estimate approaches relying on drawings, equipment activity or a few survey points. In this study, UAS and digital photogrammetry technology are adopted to estimate earthwork volumes of a highway extension project. Two 3D point cloud models are generated to track the earthwork volume changes during construction. The resulting vertical and horizontal accuracy and its dependent factors including the use of ground control points are explained and discussed. The test results in this project prove the robust capabilities of UAS in earthwork volume measurement.