The first step in constructing buildings in the new Anse du Portier district has begun this June. The feat of urban engineering known as Monaco’s seafront extension project continues to make major headway by installing the support structures for buildings which will one day fill the new neighbourhood.
A lot of precision and planning must go into the foundations of the eco-district, which extends the Principality straight into the Mediterranean sea. Near the caissons, the support structures for basements and buildings must pass through sand and limestone aggregate before reaching the foundations.
Invisible but necessary: Making the support structures
The greatest depth, 60 metres on average, is found near the caissons. Beyond this zone, a minimum depth of 17 metres must be reached. The design and size of the support structures are not identical over the entire area and vary according to the weight and shape of the buildings and the nature of the soil. Five rotary drilling rigs are being used to make the deep foundations.
As the drilling progresses, metal tubes are installed in the hole in order to prevent landslides inside the hole. When the desired depth is reached, concrete is introduced into the metal casing. The casing is equipped with reinforcement cages. This operation can take up to 10 hours for the largest supports and 5 to 7 hours on average.
Although the support structures will not be visible parts of the buildings, controlling their quality is essential. Calculations, like the quality and amount of concrete, which is poured blind, must be made.
All of the support structures are equipped with metal tubes for electric transceivers which can systematically test the quality of the structures over time. Ultrasound is used, which is translated into curves on computers. A defect on the curve corresponds to a defect in the concrete. In the event of a defect, an X-ray of the support structure is taken to find the problem.
Timeline of the project
The announcement of the land extension project happened back in 2013, but it wasn’t until 2016 when the preparation phase for construction began. End of construction is projected for 2022. Housing and commercial buildings are set to be completed in 2024, including the new harbour and Grimaldi Forum extension. The delivery of the entire district is planned for 2025.
Anse du Portier has been designed to integrate with the existing coastline of the Principality both aesthetically and environmentally. It responds to the Principality’s ambitious energy transition objectives and the need for growth in a dynamic and modern community.