Alan Davenport, analyzed wind’s effects on structures
NEW YORK - Alan G. Davenport, who devised ways to gauge the effects of wind on tall structures, then applied his expertise to some of the world’s biggest buildings and longest bridges, died July 19 in London, Ontario. He was 76.
The cause was complications of Parkinson’s disease, his son-in-law Dick Huyer said.
Mr. Davenport, a professor emeritus at the University of the Western Ontario, used mathematics and experiments with wind tunnels to estimate how far buildings can lean before they fall. He also analyzed how fast they can sway before occupants get queasy, partitions crack, or elevators get stuck.
Large structures on which Mr. Davenport consulted included the World Trade Center in New York; the Hancock Tower in Boston; the Sears (now Willis) Tower in Chicago, the CN Tower in Toronto; and the Normandy Bridge in France.
The 110-story towers of the World Trade Center were the first skyscrapers to be systematically evaluated for wind dynamics, and Mr. Davenport did the analysis of the designs. He determined that the buildings would sway too much in heavy winds. He and other engineers then invented shock absorbers to stabilize them.
In their book, “City in the Sky: The Rise and Fall of the World Trade Center’’ (2003), James Glanz and Eric Lipton, reporters for The New York Times, suggested that the devices not only buffered the effects of wind but might have also saved lives on Sept. 11, 2001, when hijacked airplanes were flown into the towers.
“Had the towers swayed more wildly after impacts, probably more sections of the stairwells would have been torn up, more escape doors jammed, and more water pipes snapped,’’ the authors wrote.
Leslie E. Robertson, a leading engineer on the World Trade Center project, said in an interview last week that Mr. Davenport’s work amounted to “a pioneering effort that had never been undertaken before.’’
He continued, “At least in wind engineering, he was a genius.’’
Mr. Davenport’s influence was widely noted.
In 1988, it was learned that the John Hancock Tower in Boston had bigger problems than windows falling out: Mr. Davenport warned that in gales, the tower risked total collapse. Extra steel beams were used to reinforce the vulnerable side.
The New Yorker said in 1995 that his studies had helped prove the need for
The Wind Engineer said in 1995 that more tall buildings were erected in the 1970s than in any other decade. It estimated that “a staggering two-thirds’’ of these were analyzed and tested by Mr. Davenport’s Boundary Layer Wind Tunnel Laboratory at Western Ontario. (Boundary layer refers to airspace close to the ground.)
