Railway Footbridge at Roche-sur-Yon

3919688634_7d28bf5080_b 3919688634_7d28bf5080_b3919733014_307098932e_b 3919733014_307098932e_b3919729956_147db193c3_o 3919729956_147db193c3_o3919726890_6e7c57b653_b 3919726890_6e7c57b653_b3919712880_e999ee304b_b 3919712880_e999ee304b_b3919709564_e799163f99_b 3919709564_e799163f99_b3919706592_2f85f4da1c_b 3919706592_2f85f4da1c_b3919705570_fd74a466a0_b 3919705570_fd74a466a0_b3919704622_731404baa2_b 3919704622_731404baa2_b3918909867_d8b209130c_b 3918909867_d8b209130c_b3919699202_2dce56e42f_b 3919699202_2dce56e42f_b3918954485_1e1dbb6a24_b 3918954485_1e1dbb6a24_b3918953993_28e87d5a44_b 3918953993_28e87d5a44_b3918953675_ce197925cd_b 3918953675_ce197925cd_b3918949431_ef2d52031b_b 3918949431_ef2d52031b_b3918947625_773f7ab84d_b 3918947625_773f7ab84d_b3918940387_7944392ede_b 3918940387_7944392ede_b3918937711_33ceffba54_b 3918937711_33ceffba54_b3918934971_611526d44b_b 3918934971_611526d44b_b3918932031_6c0910826b_b 3918932031_6c0910826b_b3918918065_24a822493b_b 3918918065_24a822493b_b3918912663_f0b10b5b50_b 3918912663_f0b10b5b50_b3918907351_662425ebd7_b 3918907351_662425ebd7_b3918900945_51beaa58df_b 3918900945_51beaa58df_b

3918896271_823e523f6d_b 3918896271_823e523f6d_b

The project for a footbridge located in Roche-sur-Yon was commissioned as a collaborative work in between HDA Paris, who has a previous experience with the footbridge they did in Turin for the Olympic Village in 2006 and Bernard Tschumi, who recently finished the Acropolis Museum.


The program for the extension of the TGV network in southern  includes a passage through the town of la Roche sur Yon. The town is modernizing the train station and replacing an 1890’s footbridge over the railway tracks. The town is separated by the railway tracks into two parts: the historical central neighborhood, which contains the ‘Pentagon’ planned by Napoleon and it’s contemporary counterpart with its modern facilities (stadium, school and residential zones).The ambition of the town, is not only to create a symbolic link between the two neighborhoods, but equally to celebrate the arrival of the TGV.La Roche sur Yon is the birthplace of Robert le Ricolais, engineer, architect, poet and painter, known for his theoretical research on trellis structures and tensegrity during the 1950’s. This heritage, both intellectual and historical, has inspired the design of the new footbridge by attempting maximum lightness. During the design process therefore HDA combined structural optimization with the architectural concepts by creating a full height filigree lattice tube, that provides not only a support for safety meshes as required by the railway authority, but also maximum structural inertia.The diagonal lattice design recalls the existing old riveted footbridge. At the support points, the stresses are mainly shear, in the predominantly vertical direction, and at mid-span, the stresses become principally bending and the direction tends towards the horizontal. The natures of the forces are highlighted by ‘T’ or ‘H’ section profiles for compression and simple rod ties for those in tension. The transition between supports and mid-spans is also underlined by the presence of vertical circles that recreate links for the shear force transfer. The architectural result is an expression of the natural forces.

It is interesting to consider that the structural optimization process that permits, saving tons of material is not only driven by practical, aesthetic and economic objectives, but also has an ecological dividend.  itself is a recyclable material to begin with. From the initial analyses, where all  sections were identical, the tonnage was reduced considerably using subsequent iterative analyses, and notably by replacing the tension members with thin rods. This also significantly contributed to a delicateness in the architectural quality.

A real scale prototype is now complete and the footbridge construction is in progress and the final delivery is planned during 2009.




Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: