User:IIIIMajestic/Millau Viaduct

Introduction

On December 14th 2004, after 3 years of construction, the highest bridge in the world was inaugurated: the Millau Viaduct. Located next to Millau, Midi-Pyrénées (South of France), this gigantic cable-stayed bridge crosses the valley of the Tarn River. This work can definitely be considered as a structural art masterpiece, by attaining excellence in the three areas of efficiency, economy, and elegance, as defined by Professor David P. Billington of Princeton University. The study of this imposing massive structure from a scientific, an economic-social, and a symbolic point of view will bring a proof to this statement.

Structural Description

From a scientific perspective, the Millau Viaduct is the fruit of technological prowess. The 32 meters wide steel deck of the Millau viaduct, made up of 173 central box beams, constitutes the backbone of the structure and weights 36,000 tones. A surface made of bituminous concrete has been added to it to deal with its expansions. This surface is flexible enough to adapt the deformation of steel without cracking. Each pylon is equipped with 11 pairs of stays placed face to face, themselves made of 45 to 91 steel cables, each made of 7 triply protected steel strands (by galvanization, a coating of petroleum wax and a extruded polyethylene sheath). Loads are transmitted from the deck (in compression) to the stays (in tension) then to the piers (in compression), and ultimately to the ground. Under each of the 7 piers, 4 wells, 9 to 18 meters deep, spread the weight and ensure the foundations and stability of the viaduct.

From an economic-social point of view, the entire project cost 400 millions euros, which is relatively cheap for such a gigantic work. It has had a direct positive impact on the economy of the region by making areas more easily accessible and by saving in average 1h16min and 47,40 euros (from toll) to get to Paris from the south of France. The Millau Viaduct allows the crossing of more than 4.5 millions vehicles each year, and thus plays a key role in the traffic regulation of the region.

From a symbolic perspective, the Millau Viaduct owes its charisma in part to records it broke, since it is the highest road bridge deck in the world (890 ft above the Tarn River at its highest point). It also possesses the highest bridge tower since P2 peaks at 1,125 ft, as well as the tallest pylons (P2 culminates at 803 ft and P3 peaks at 725 ft). Moreover, thanks to its elegance and its slender design, it fits perfectly into the landscape, and “its thin deck supported by long stays confers its sailboat gaits.”

Qualification as Structural Art

Thus, having considered the Millau Viaduct through scientific, social and symbolic lenses, one can conclude that it constitutes a masterpiece. Due to its magnitude, both social and physical, it represents an efficient, economical and elegant work that could be qualified of structural art.