Semapa: Laying Public Spaces

structures for the Seine Rive Gauche project

Semapa: Laying Public Spaces

The Seine Rive Gauche urban planning project in Paris (13th district) at the Bibliothèque Nationale de France is continuing.

After the installation of the T4 zone 7 slab in the first quarter of 2018, Matière® has entered the phase of setting up the Public Spaces (EP2, EP3 and EP4) to cover the railway right-of-way


Some technical details of the structures

The 3 EP2, EP3 and EP4 structures are composite steel-concrete structures composed of a reinforced concrete slab and metal girders equipped with an intumescent anticorrosion system. Each deck consists of main metal I-beam.


Structures EP2 and EP3:


  • 4 I-beams lengths between 36.35 m and 38.07 m approximately;
  • Their heights vary between 1.93 m (EP2) / 2.34 m (EP3) on the Avenue de France side and 3.02 m (EP2) / 3.19 m (EP3) side aisle planted;
  • 5 pieces of I-beam bridges with heights of 1.68 m on EP2 and 2.06 m on EP3 between the central beams constitute the transverse secondary beam;
  • Total weight EP2: 200 t, total weight EP3: 200 t.



Matiere work site in Paris 13th




EP4 structure:


  • 8 I-beams between 48.6 m and 49 m approximately;
  • Their heights vary between 1.68 m on the Avenue de France and 2.67 m on the driveway;
  • The bracing between the beams of the same scale consists of diaphragm;
  • The spacing between ladder beams is made with HEA200 profiles between the lower and upper flanges arranged between beams P2-P3, P4-P5 and P6-P7;
  • Total weight EP4: 402 t.




structures for the Seine Rive Gauche project



Focus on the construction site of Public Spaces


The structures for the Seine Rive Gauche project were manufactured by the Charmes factory in Les Vosges and supplied on site thanks to 16 exceptional convoys. The beams were transported by half-scale (50 t on average) then unloaded with 2 cranes of 130 t on the central reservation of the Avenue de France.


The poses of the various ladder beams required the installation of a crane of 750 t. In fact, for the installation of our structures, we had to switch an EP4 ladder beam from 110 to 30m in height. Because of its position on the concrete slab of the Avenue de France, it was necessary to make different arrangements to wedge the crane to take the concrete beams of the Avenue, themselves spaced 16 m.


During these preparations, we used a temporary Unibridge® bridge to install the crane in charge of laying the 4 EP4 ladder beams without using a superlift and thus optimize the operation.

The installation of the various metal elements took place in August, October and December. Work on these 3 structures will be completed in early 2019 with the installation of the EP4 spacers and the support of the 3 public spaces.


For the record the concrete slabs equipping these structures were provided by our factory of Brive-la-Gaillarde.

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