Concrete bridge articulation

Abstract

This paper demonstrates to bridge designers the advantages of matching bearing stiffness to pier stiffness to achieve economic load sharing of longitudinal loads on concrete bridges. The paper discusses the types of bearings and their limitations for articulation, bridge movements and horizontal loads, and sets out the design process for a bridge supported and restrained by elastomeric bearings only - an elastically restrained structure. An example of the calculations at a typical pier is given. The following articulation systems for a continuous bridge example are analysed, the results tabulated and compared: pinned and sliding, monolithic and elastomeric, pinned and elastomeric, all elastomeric bearings. The following articulation systems for a simply supported bridge example are analysed, the results tabulated and compared: pinned and sliding, pinned and elastomeric, all elastomeric bearings. The paper concludes that matching bearing stiffness to pier stiffness produces cost savings; that elastomeric bearings are superior for this purpose, that elastically restrained bridges give the best load sharing amongst piers and that load sharing can be improved with sliding bearings by varying the coefficient of friction (a).