Walter Podolny Jr., 84, a bridge design expert and former senior structural engineer at the U.S. Federal Highway Administration, died on Sept. 26 in Burke, Va. The cause of death was a heart attack, his family confirms. Podolny was a much published author, whose works include a 1982 book with engineer Jean Muller on construction and design of prestressed concrete segmental bridges. He also co-authored a 1986 book on cable-stayed bridge design. A memorial service is set for Nov. 22 in Annandale, Va.
Podolny noted in a 1997 ENR article that FHWA was evaluating solutions to a problem of vibrations being induced on cable-stayed bridges from a combination of light rain and moderate wind, which caused oscillations on the order of 3 to 4 ft in 650-ft-long cables. This situation was partially responsible for a month-long closure in 1996 of the Erasmus Bridge in Rotterdam, Holland, and had caused noticeable cable vibrations in bridges in Texas and Iowa. He said the rain spins around the cable, changing the cross section aerodynamics and causing the fluctuation. According to Podolny, FHWA had been looking at fixes that included dynamic dampers and tuning ropes that link the stays together. Both systems had proved partially successful on France's Normandy Bridge, which was opened in early 1995 and was, at the time, the world's longest cable-stayed bridge.