Abstract
A lot of fatigue damage has been reported in steel highway bridges sustaining great number of heavy trucks, and the fatigue assessments have been specified explicitly from the revised edition of “the Design Specification for Steel Highway Bridges” in March 2002. A concrete manner of the assessments is specified in “the Fatigue Design Recommendations for Steel Highway Bridges”. Fatigue design load specified in the Recommendations is based on the T load whose weight is modified by T-load correction factor, simultaneous loading factor and fatigue impact factor.
In this paper, the simultaneous loading factor has been discussed, which is considering the effect of the increment of the stress on fatigue behavior by simultaneous multi-presence of vehicles on the bridge.
