A new type of parallel wire strandsl were developed for stays on cable-stayed bridges. A strand consists of slightly helically twisted wires with high fatigue resistant sockets. The results of fatigue tests for these socketed cables were presented. A design non-dimensional S-N curve was proposed for these new cables. Stays may suffer considerable stress fluctuation when cables oscillate due to winds or vehicles on the bridge. Cable normal and secondary bending stresses due to the oscillation

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... e obtained analytically with some consideration on the effect of support conditions. Fatigue lives due to random traffic were investigated by a simulation method for the three-span cable-stayed bridge. Cables show different fatigue lives depending on the position of the bridge and the shape of influence lines. A simple method was then proposed to predict fatigue damages and proved effective.