Innovative offshore engineering to protect Venice from flooding
The storm surge barrier consists of 78 hollow steel gates hinged to massive reinforced concrete caissons founded on the seabed. To enable the accurate installation of these heavy caissons, MH Poly developed a specialised installation pontoon in collaboration with marine contractor Strukton and engineering partner Haak en Van Ham.
The project required an integrated combination of offshore engineering, civil engineering, hydrodynamics and structural analysis. Despite an exceptionally short engineering schedule, the complete detailed design was successfully delivered within just nine weeks.
Design of a specialised installation pontoon
The installation pontoon was specifically designed for the controlled lowering and precise positioning of reinforced concrete caissons into a prepared trench on the seabed near Chioggia, on the southern side of the Venetian Lagoon. Due to the enormous dimensions and weight of the caissons, vessel stability, wave loading and positioning accuracy were critical design considerations.
MH Poly was responsible for the dynamic analyses of pontoon behaviour under wave loading, stability assessments in accordance with DNV guidelines, and structural calculations for the complete lifting configuration. Extensive physical model tests were subsequently carried out at Deltares to validate the dynamic behaviour of the system.
Through close collaboration between structural engineers, offshore specialists and immersion experts, the team delivered an economically efficient and technically robust design that met the stringent requirements of the MOSE Project.
Technical challenges within an exceptionally short schedule
The greatest challenge of this international marine infrastructure project was the extremely limited engineering timeframe. From the final system selection to delivery of the detailed design, the entire engineering process was completed in only nine weeks.
Despite this demanding schedule, MH Poly delivered a fully engineered solution, including numerical models, stability analyses, lifting calculations, structural verifications and detailed fabrication drawings. Efficient collaboration between all project partners resulted in a technically sound and cost-effective solution delivered within the required timeframe.
MH Poly's scope of work
- Establishing the engineering basis and design criteria (Design Basis);
- Developing numerical models to analyse dynamic behaviour under wave loading;
- Performing pontoon stability analyses in accordance with DNV guidelines;
- Conducting a concept and optimisation study for lifting frames;
- Performing structural analyses of the pontoon and complete lifting configuration using SCIA Engineer;
- Calculating winch capacities for 60-tonne winches;
- Performing structural calculations for the connection points between the lifting block and the caisson;
- Performing structural calculations for 500-tonne lifting blocks;
- Producing fabrication drawings for lifting frames, connection details and deck layout;
- Developing a complete 3D model of the pontoon and caisson in Autodesk Inventor for engineering and presentation purposes.
