The Use of Lidar in Mapping and Assessing Bedrock Foundations-Video

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Video Summary

Geologists with the U.S. Army Corps of Engineers used LiDAR to map bedrock foundations during construction of a modified stilling basin at Bluestone Dam, West Virginia. Detailed records were needed because the foundations would be covered by concrete and could later inform inspections, risk assessments, and dam-safety decisions.<br /><br />Using a Trimble scanning total station, the team captured cleaned, prepared foundation surfaces, processed the scans into georeferenced orthophotos and 3D topographic models, then traced geological features onto scaled maps. The method required little training and used district equipment. Compared with traditional grid-based mapping, it was more accurate and roughly 50–75% faster, reducing exposure of the foundation to weathering and the dam toe to scour and uplift risks.<br /><br />Key lessons included scanning the entire prepared area at once, minimizing people and equipment in view, and favoring overcast lighting. The team plans to refine the approach and explore tablets, drones, automated structural measurements, and virtual-reality inspections.

Keywords

LiDAR mapping

Bluestone Dam

bedrock foundations

Trimble scanning total station

georeferenced orthophotos

dam safety inspections