Abstract
The purpose of this study is to identify the causes of fatigue cracks found in a plate girder-on-steel frame pier bridge. The complexities of this type of structure make the stress configurations near crack locations complicated. A three-dimensional finite element model, incorporating both superstructure and substructure was created to study the stress development mechanisms near crack locations. Field tests were carried out to investigate structural behaviors, such as conditions of bridge bearings, and to validate the finite element modeling. The results indicate that fatigue cracks are caused by dysfunctional bridge bearings, poor structural details and deformations of some members.
