Calculation of the Objective Service State in Cable-Stayed Bridges

The resistant mechanisms that govern the structural behavior of cable-stayed bridges depend, to a greater or lesser extent, on the tensile forces of the stays. This makes possible to adjust the internal force distribution under a certain load hypothesis, target load, TL, towards an optimal stress state to fully utilize material strength or minimize structural costs. If this optimal state is to be achieved at the completion of the bridge, it is known as Objective Service State, OSS. Despite its influence in the structural behavior of the structure, the calculation of the tensile forces in the stays in this stage is a complex process as a variation of tensile force in any stay modifies the tensile forces of all already placed stays. As the available methods to define these tensile forces are not always known by the practitioners, five of the most commonly used criteria are reviewed in this paper.