An evaluation of the fatigue life of the benicia-martinez bridgewas undertaken in anticipation of the widening of the bridge. this 1.2 mile long, high level crossing includes ten steel deck-truss spans up to 528 ft in length. welded built-up h sections of t-1 and astm a242 steel were used for the truss members. stay plates were also fillet welded to the flanges of the h-sections at the joints, apparently to offset the loss of section due to bolt holes. cracking had been found at several fillet weld terminations of the stay plates prior to the evaluation. subsequent examination during the course of the evaluation confirmed that fatigue crack growth had occurred, even though most of the previously-observed cracking was related to fabrication. a state-of-the-art evaluation of the fatigue life was made using strain data recorded under normal traffic. this evaluation revealed that, on a conservative basis, the fatigue life was nearly exhausted. details to remove the fatigue-sensitive conditions were developed and subsequently implemented. this paper appears in transportation research record no. 1290, third bridge engineering conference, march 10-13, 1991, denver, colorado, volume.1
Abstract