Analysis of innovative two-span suspension bridges

Abstract

Recently, two-span, or the so-called single pylon suspension bridges, due to their constructing structure, have been widely applied. A reduction in deformation seems to be the main problem of the behaviour and design of such bridges. The deformation of suspension bridges is mainly determined by cable kinematic displacements caused by temporary loadings rather than by elastic deformations. Not all known methods for the stabilization of the initial form of suspension bridges are suitable for single pylon bridges. The employment of the so-called rigid cables that increase the general stiffness of the suspension bridge appears to be one of the innovative methods for stabilizing the initial form of single pylon suspension bridges. Rigid cables are designed from standard steel profiles and, compared to the common ones made of spiral and parallel wires, are more resistant to corrosion. Moreover, the construction joints, in terms of fabrication and installation, have a simpler form. However, calculation methods for such single pylon suspension bridges with rigid cables are not sufficiently prepared. Only single publications on the analysis of the behaviour of one or three-span suspension bridges with rigid cables have been available so far. The paper presents analytical expressions to calculate the displacements and internal forces of suspension bridges with rigid cables thus assessing the sequence of cable installation. Also, the paper describes the sequence of iterative calculation.