Proposed revisions to fatigue provisions of orthotropic steel deck systems for long span cable bridges

Long span cable bridges, especially cable-stayed bridges or suspension bridges having record-breaking span length, have been constructed using orthotropic steel deck systems, because of light self-weight of the steel superstructure. In addition to extended span length, the bridges are requested to serve for a longer time, e.g., 200 years, which makes the bridges experience high cycle loadings and fatigue become a governing design factor. This paper summarizes research results obtained from computational analyses and experiments using 2-dimensional as well as 3-dimensional structural models. Based on the results, revisions to Korean design manual for cable-stayed and suspension bridges including new Korean models of fatigue strength curves and standard configuration of connection details are proposed in order to enhance fatigue resistance of the orthotropic steel deck systems serving for a prolonged design life.