The Design and Construction of Canal du Midi, an ASCE IHCEL, in Southern France

摘要

The Canal du Midi (originally named: Royal Canal in Languedoc), connecting boat traffic from the Mediterranean to Atlantic or return, was constructed from 1666 to 1681 during the reign of Louis the XIV and was the largest European public works construction project since the Roman Empire. Constructed under tax collector Pierre Paul Riquet's supervision, the 240 km (150 mi) canal had a navigable depth of 1.8 m (6 ft), an average bottom width of 13 m (42 ft), and overcame an elevation increase of 190 m (625 ft). The Canal du Midi is a summit canal, climbing from Toulouse over a distance of 52 km (32.3 mi) to the Seuil at Naurouze summit (189.43 m altitude) and continues 188 km (118 mi.) to the Mediterranean Sea. In addition to the manual excavation of the canal, the project required the construction of 328 separate structures, including 91 locks and more than 126 bridges, dams, diversion structures, and two tunnels. The main structures are presented: (1) St. Ferreol Dam and Reservoir [780 m or 2,560 ft long and 32 m or 105 ft high (the largest in the Western Hemisphere when built and second highest European dam then)], the stored water could be released in either direction through an ingenious two-gated basin near the summit to augment natural flows entering the canal; (2) the Malpas tunnel (165 m, 541.3 ft) through a mountain excavated by explosives (and the first canal passage ever built through a tunnel) and the Cammazes tunnel (constructed by the great French engineer Vauban more than 10 years after the canal was completed), which brings water from a diversion at Alzau into the St. Ferreol reservoir; (3) the three-gated circular lock which allows watercraft to continue on the canal or turn 90 degrees and exit to the existing Mediterranean port at Agde; and (4) the construction of the flight of eight original locks at Fonseranes (reduced to seven locks in a modernization) with 10,000 boat passages per year. Under the Act of 27 November 1897, the State of France owns the Canal du Midi, and its management is delegated to Voies Navigables de France, in the Ministry of Transport. Busier than the River Seine, the canal accounts for 1/5 of French river tourism and 80% of the passengers are Germans, Swiss, and British. The Canal du Midi was designated as a UNESCO World Heritage Site in 1996 and an ASCE International Historic Civil Engineering Landmark in 2016.