Initial Cable-Forces Adjustments in Cable–Stayed Bridges: Effects of Parameters Uncertainties

Initial cable-force determination for long span cable-stayed bridges is an important first step in the analysis of bridge performance under external loads. For a good adjusting of cable system, an accurate assessment of these is required. The observance of execution tolerances allows, at least at the beginning, to take some of these parameters as deterministic. Moreover the statistic assessment of actual loads during bridge assembly ensures the correct evaluation of the effects of their variation. In this paper a new procedure of this problem is shown, the technique does not require a large computational effort and computer memory. Approximating the probability density distributions of the variables with Gauss curves, we get a closed form formulation of imposed elongations of stays during erection. In this way can be obtained an accurate prediction of the distribution of probability density of profile and stress fields of bridge.