The group of contractors in charge of constructing the dikes and protecting structures entrusted Terrasol with a consultant mission, i.e. the geotechnical justification of the stability of the various structures: enclosure dikes of the hydraulic filling caissons for the constitution of the terrepleins (total length 4 km), external dikes (5.9 km), slope of the access channel, and foundations of the pier heads.
This design work could take advantage of detailed testing campaigns led by Port Autonome du Havre when preparing the project, and of the specific additional surveys led within detailed design, on the ground or by sea.
Special attention was paid to hydraulic phenomena related to tides: specific observations led during the works allowed to validate the calculation assumptions.
The concrete caissons to be installed by flotation on the pier heads were also exceptional structures due to their dimensions: 56 m x 21 m, 26 m high and their weight: 13,000 t before filling, 40,000 t after filling. Their foundation required special focus, for surveys and specific testing which were carried out, for checkings led within the framework of the ROSA 2000 recommendations, and for the evaluation of the displacements during installation or service phases.
Terrasol’s achievements:
Expertise of the structures stability:
- Enclosure dikes
- External dikes
- Slope of the access channel
- Pier head foundations