LAZARD

FRANCE (see also List of Individuals)

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9.1.1910 Valenciennes/F - 20.1.2003 Paris/F

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Achille Lazard graduated from Ecole Polytechnique and Ecole des Ponts et Chaussées to continue in the latter Corps as an engineer from 1933. After World War II he was involved in dam engineering, such as the Bort-les-Orgues Dam in Central France taken into service in 1952. The arch dam is 124 m high and owned by Electricité de France EDF. In 1947 Lazard left hydraulic engineering to collaborate with the national railroad company SNCF as a civil engineer. He was involved in dam engineering, particularly in the Serre-Ponçon Dam in the French Department Hautes-Alpes, the first large earth dam of France. This notable engineering work was designed by Coyne et Bellier directed then by Jean Bellier (1905-1986), it is 124 m high and has a volume of 14 Mio m3. The scheme was taken into service in 1960. From then, Lazard was the general vice-secretary and honorary director of SNCF. He also was an active Member of Société des Ingénieurs Civil de France.

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Lazard is known in hydraulics for his 1947 paper on backwater curves in which the approach of Georges Mouret (1850-1936) is developed. Once the basic equation of backwater curves established, Lazard considered various channel profiles including the rectangular and the circular-shaped pipe. The general properties of backwater curves are then described, including the asymptotic features for zero, and infinite flow depth. Also, the transitions from subcritical to supercritical flows, and the inverse conditions resulting in a hydraulic jump are outlined. This approach was further developed by the American Ven Te Chow in 1955, and popularized with the 1959 book, in which a large review on backwater curves is presented.

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_{Anonymous (1955). Achille Lazard, Ingénieur en chef des Ponts et Chaussées, Société Nationale des Chemins de Fer Français, Voie et Bâtiments. 5 ICOLD Congress Paris 1: 110. P}

_{Anonymous (1968). Lazard, Achille. Who's who in France 1967-1968: 821. Chow, V.T. (1959). Open-channel hydraulics. McGraw-Hill: New York.}

_{Lazard, A. (1935). Les pertes de charge dans les conduites. Revue Générale de l'Electricité 38: 387-401.}

_{Lazard, A. (1947). Contribution à l'étude théorique du mouvement graduellement varié en hydraulique. Annales des Ponts et Chaussées 117(3/4): 185-219.}

_{Lazard, R. (2003). Achille Lazard. Personal communication.}

_{Ramunni, G., Savio, M. (1995). Lazard, Achille. 1894-1994 Cent ans d'histoire de l'Ecole Supérieure d'Electricité: 265. Saxifrage: Paris.}