Scan to BIM for arc bridge in Austria

The client specializes in capturing infrastructure objects to create digital models, extracting real textures from photos, and applying them to the model. This process serves as vital documentation for identifying damages like cracks, corrosion, etc. Based on these models, building inspection reports are generated, and further plans for reconstruction and maintenance are developed.

The client employs photogrammetry technology based on drone-taken photos, particularly chosen for its ability to access low-accessibility areas compared to standard scanners or digital cameras.

Scope of work: Precise modeling of the concrete arch bridge and the adjacent ground surface.

Input: Full Point Cloud of the bridge and adjacent area obtained through photogrammetry (drone capture).

Output: 3D Model of the bridge at LOD300.

The project’s main challenges were rooted in the use of drones to capture point cloud data. Although this method offers advantages like accessibility to remote locations and cost efficiency, the received data is often quite noisy. Points may not create perfectly distinguishable surfaces and can be scattered with some inaccuracy, demanding extra effort from the team to process.

Additionally, issues like doubling or tripling the point cloud data with offsets relative to one another often occur. Solutions involve requesting reprocessing from the data provider or manually analyzing the data, but the latter cannot guarantee accuracy.

Unlike standard buildings, bridges usually don’t have orthogonal geometry. They might be curved in plan view and have elevation changes in side view, making classical Revit tools not fully suitable for bridge surface modeling.

The team developed a suitable method by creating cross-section outlines with a specific step in sectioning. Using the mass tool, they created smooth curved objects through the previously drawn cross-sections. The result is a precise model of a curved element, facilitating the application of textures.