The Cheviré bridge in Nantes – J. Urbach / 20 Minutes
- The Cheviré bridge was inaugurated on April 27, 1991.
- Spectacular, it measures 1.5 km long and 52 m high.
- It allows the western ring road of Nantes to cross the Loire without hindering the passage of boats.
It dominates the west of Nantes and the Loire for 30 years. On April 27, 1991, after four and a half years of work, the Cheviré bridge was
inaugurated by Prime Minister Michel Rocard. Although it is not the largest bridge in Loire-Atlantique despite its 1,560 m long and 52 m high (that of Saint-Nazaire is
even more impressive), Cheviré is today the most traversed of the Great West. Almost 110,000 vehicles used it in 2019, against 40,000 when it started and 85,000 in 2001. Given its number of visitors and its age, the structure is therefore subject to regular and close monitoring.
“Every year, we carry out a control visit, on foot and simply visually,” explains Lionel Garrispe, head of the civil engineering structure management unit for the Interdepartmental Directorate of West Roads. Every three years, a more in-depth inspection is also carried out during which the work is noted. Finally, every six years there is a detailed visit carried out by the
Cerema, using nacelles and rope access technicians. It’s quite long and spectacular. We examine all parts of the structure, including the interior since we can enter the box. The next one will take place in 2025. “
“He is doing very well”
There are also sensors in the body of the structure which make it possible to follow the expansion of the bridge. “All materials expand with temperature. It’s normal. In summer it tends to lie down and in winter to retract. The difference is of the order of ten centimeters. “
Assessment of the various consultations: “The Cheviré bridge is doing very well, reassures Lionel Garrispe. No major intervention was necessary. Reinforced concrete is a robust material and as long as there is no observed defect, nothing can be done. It is especially important to be attentive to the parts of wear which must be renewed regularly: the pavements, the joints of the pavement, the retaining devices… ”
Pavement work to be planned
Unlike other bridges, such as those at Bellevue or Saint-Nazaire, no pile is submerged, which “facilitates maintenance”. The pavements located on the concrete part were redone in 2014 and 2017. “We still have to redo the pavement on the central metal part. It will not be before 2023. This is substantial work. »In 2015 and again in 2019, the Cheviré bridge was changed from two to three lanes of traffic in each direction in order to reduce traffic jams. This development enabled an average time saving of between 3 and 7 minutes at peak times, according to the Dir-Ouest
As for the yellow lampposts on the bridge, they have not worked since 2008 following the theft of cables. “There is no re-lighting project,” says Lionel Garrispe. However, the candelabras should not be removed as “they are part of the architecture”.