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Abstract

The Wheeling suspension bridge failed in 1854 due to torsional resonance in the wind. Indeed, suspension bridges were particularly prone to failure. Alfred Pugsley, a well known expert, estimated that 120 suspension bridges were built between 1800 and 1900, with an average life of forty years and a one-in-seven failure rate, which was about ten times the rate for ordinary bridges. The current rate is about one in lour thousand. The collapse of the Duplessis Bridge in Quebec in 1961, following by the Kings Bridge collapse in Melbourne, Australia, in 1962, demonstrated the critical nature of the brittle I'acture ol steel and the need for the careful specification of steel intended to be welded. Just like the 'beeling Bridge, the bridge of Tacoma Narrows in USA was aerodynamically unstable. The bridge was nicknamed "Galloping Gertie" because of its motion under quite light winds, which not only caused it to swatrom side to side hut also sent riipling waes along the deck. Attempts were made to dampen the movement with additional slays, hut n ithoul success. In 1940 a moderate wind of around 42 mph set up severe lateral twisting ol the deck as well as longitudinal rippling. The failures of Fourth Danube Bridge in Vienna in 1969 and of Milford Haven in Wales and 'estgale Bridge in Melbourne 1970 highlighted the quit different dual needs lor better understanding of plate buckling in box girders and of construction management. One of the world's largest bridge catastrophe was in the early hours ot January 18" 1980. about 1.30 pm, the original "Almobridge" in Sweden, met it's disasterious misfortune. A cargo vessel "Star Clipper", 30 000 tons, collided with the bridge, totally demolishing it's arches and foundations. Before the traffic over the bridge could be stopped, 8 unfortunate people died, driving their vehicles over the edge.