Analysis of modern three-span suspension bridges with stiff in bending cables

Abstract

Suspension bridges are one of the most effective bridge structures used for large spans to overlap. Recently, not only the single-span bridges but also multi-span suspension bridges have been used. The main issue of design and analysis shall consider the excessive deformability induced by the interaction of flexible and kinematic displacement. Stabilization of suspension bridges could be ensured by various means. The most effective and up-to-date measure applied to reduce displacements of suspension bridges is the application of the so-called “rigid” cables with appropriate bending stiffness instead of conventional flexible cables. These retaining elements demonstrate high corrosion stability; their cross-sections are designed using conventional structural steel sections, factory and fabricated connections are simple and firm. The main advanced feature of these cables is that these elements along with the suspended stiffening girder stabilize the initial shape of the bridge effectively. It shall be noted that analysis methods applied for these innovative three-span suspension bridges with “rigid” cables are still under development. There are only few individual publications describing the behaviour of a single-span suspension bridge. The article describes the modern suspension three-span bridge and provides analytic expressions of internal forces and displacements calculated considering the erection sequence.