"wavelike" - 1 õppematerjal

Bridges presentation

Pennsylvania, which he later moved to Trenton, New Jersey. Educated in Europe, he would have been exposed to the concepts of wire-cable suspension bridge engineering of the French and Swiss. He and Ellet competed for primacy in suspension bridge design. Roebling won out when he took over design of the Niagara Suspension Bridge from Ellet, successfully completing it in 1855 (Figure 17). The inherent tendency of suspension bridges to sway and undulate in wavelike motions under repeated rhythmic loads such as marching soldiers or the wind was not completely understood by engineers until the 1940s, following the collapse of the Tacoma Narrows Bridge ("Galloping Gertie"). Credit for designing the first suspension bridge rigid enough to withstand wind loads and the highly concentrated loadings of locomotives belongs to John Roebling. His first masterpiece was the Niagara Suspension Bridge, with a span of 821ft (250m) on the Grand Trunk Railway below