Restoration of a Complex Building with Challenging Timeline

Context

Built in 1897 to replace the "Palais de I'Industrie" , the "Grand Palais" has been set up for the "Exposition Universelle" in 1900, in Paris -- like the "Petit Palais" and the bridge Alexandre III. Its architects, Deglane, Louvet and Thomas were confronted with a complex order: to design a palace with monumental proportions in the historical environment of the Champs-Elysées. The construction consisted of a metal framework equipped with a coating of stone. The entire project has a surface area of 35,000 m2 on the ground, extending to a height of 40 m. To site such a building on ground that was primarily unstable clay the designers chose a pile foundation.

Over time, the ground water level increased due to movements of the Seine, that generated an erosion of the pile heads. As of today, the southern part of the building sank 10 cm.

Solution

To stop the building to sink, the Ministry of Culture began rehabilitation works underneath the existing structure, that consisted of transmitting the vertical loads from the existing masonry to slurry trench walls and jet grouted columns. To transmit these loads, the soles in masonry walls are surrounded by armed concrete blocks secured by prestressed DYWIDAG Bars. The bars are installed in cement grouted metal sheaths to ensure proper corrosion protection.

DYWIDAG performed the complete installation of the prestressing system (installation and grouting) with all the difficulties that such a complex building site presents.The crews faced constant challenges in adapting their work to the confined work areas and found solutions to anchor the bars into non-accessible parts of masonry. DYWIDAG´s experience in the field, combined with a close relationship with the customer, made it possible to conclude its work on this complex building site on time while maintaining an exceptional level of quality.