LAURSEN

LAURSEN 24.01. 1919 Fairmount ND/USA 17.10. 2013 Tucson AZ/USA Emmett Morton Laursen obtained the BCE degree from University of Minnesota, Minneapolis MN, in 1941, and the PhD degree from University of Iowa, Iowa City IA in 1958. He was from 1941 to 1942 an assistant at the Hydraulics Laboratory, University of Minnesota, junior engineer at a design company in Colorado until 1945, from when he joined the Iowa Institute of Hydraulic Research IIHR as assistant, research associate, and research engineer until 1958. He was then associate professor of civil engineering at Michigan State University, East Lansing MI until 1962, from when he was until retirement professor of civil engineering and head of department, University of Arizona, Tucson AZ. From 1985 Laursen was a private consultant. He was awarded the 1959 ASCE Hilgard Prize, and the 1961 ASCE Research Prize. Laursen also was Honorary Member ASCE, and a member of the International Association of Hydraulic Research IAHR, and of AGU. Laursen was known for his research in sediment transport, fluid mechanics and its applications. He counted to the first Americans dealing with scour, an issue previously tackled mainly in Europe. Scour may be described as localized erosion mainly due to flow concentrations including jets and vortices. It may seriously damage structures erected in water, such as bridge piers and abutments. The 1962 paper attracted numerous discussions, stating a vital interest in this ‘new topic’ in the USA. During this period, mainly the maximum scour depth was considered, whereas the temporal scour hole advance was overlooked. The 1963 paper investigates scour in a contraction using mass and energy considerations coupled with a sediment transport index and a uniform flow equation. The result is a relation for scour depth as a function of channel geometry, discharge and sediment characteristics. The abutment as a special case was also studied. Anonymous (1959). Emmett M. Laursen. Civil Engineering 29(10): 74-75. P Anonymous (1962). Emmett M. Laursen. Civil Engineering 32(7): 65. P Anonymous (1988). Laursen. Civil Engineering 58(12): 92. P Anonymous (2000). Emmett M. Laursen. ASCE News (11): 2. P Laursen, E.M. (1958). The total sediment load of streams. Journal of the Hydraulics Division ASCE 84(HY1): 1-36. Laursen, E.M. (1962). Scour at bridge crossings. Trans. ASCE 127: 166-179; 127: 207-209. Laursen, E.M. (1963). Analysis of relief bridge scour. Journal of the Hydraulics Division ASCE 89(HY3): 93-118; 90(HY1): 287; 90(HY4): 231.