Projects 
tignes dam
Tignes Dam — 3D Modelling & Inspection (2020)
The highest dam in France: 180 metres!
Several thousand square metres were digitised at a resolution of 2 mm per pixel to examine the structure in minute detail as part of its ten-year inspection.
The survey team also descended the downstream face on ropes to carry out thermographic spot measurements — a rare chance to experience such grandiose vertigo...
2020
Client
EDF
Owner’s Engineer
Ing’Europ
Undertaken for EDF in 2020, the project required Geokali’s pilots to operate drones for extended periods only a few metres from the dam face — a demanding exercise in precision and endurance.
In addition to the 3D survey, Geokali produces inspection reports on reinforced-concrete structures.
These reports include:
– interactive boards, where each defect is identified by a clickable icon linking to a detailed photograph of the observation;
– a written report describing the survey conditions and methodology, and providing commentary on each recorded observation.
This was the first operation using a new generation of drones, which confirmed image quality, reliability and stability under the strong thermal currents along the downstream face of the dam.
Rope-access operations to perform localised thermographic surveys.
High-precision static scanners — with extremely low noise levels (manufactured by Zoller & Fröhlich) — fulfil a dual role: providing geometric constraints during 3D model generation and a reference dataset for quality control.
Evaluating the geometric reliability of a photogrammetric model, controlling potential drift and maintaining accurate image correlation is particularly complex and labour-intensive when dealing with large structures.
The contribution of the laser-scanned point cloud is key, both in the field and in post-processing, improving reliability and control over the production workflow — and ultimately, cost efficiency.
3D model view of the downstream face
3D model view of the upstream face
Projects