Preliminary Design of Prestressed Concrete Stress Ribbon Bridge

Abstract

A stress ribbon bridge is a very slender structure in which the deck hangs in a suspended cablelike form. The structural response of this kind of structure is complex because of the combined effects of geometric nonlinearity, prestressing, and time-dependent materials behavior, and it has not been fully presented yet. However, since the introduction of this new structural type in the 1960s, a considerable number of stress ribbon bridges have been built. The structural behavior of prestressed concrete stress ribbon bridges is presented emphasizing the geometrical nonlinear character of the equations and the effects of creep and shrinkage of concrete. Analytical equations are integrated for the particular case of a built-in stress ribbon bridge, allowing for the determination of the effects of posttensioning, evenly distributed live load, and temperature variation. Expressions are given for the calculation of the vibration frequencies. A preliminary design of an 80-m built-in stress ribbon bridge is finally worked out based on the presented formulation.