Evaluation and Repair of Wrought Iron and - Purdue e-Pubs ...

120so that they would act in symmetry again. Also, the deck and certain members werereplaced, and the bridge was sandblasted and repainted. The overall cost of the bridgerehabilitation was $300,000 dollars and the operating rating for H and HS trucks was 23and 37 tons, respectively (Taavoni, 1994). This proved to be a very affordable method torehabilitate this bridge for the state of Maryland.5.4 Investigation of Crack Growth in EyebarsWhen investigating the capacity of pin connections of an existing historicwrought iron truss bridge, it is also important to investigate the strength of theconnections at the end of the eyebars of the bottom tension cord. These eyebars aretypically fracture critical members and should be thoroughly checked for any sign ofdistress due to fatigue or corrosion.The eyebar end connections found from the historic wrought iron trusses have avariety of different geometries. Under dynamic and cyclic conditions, the strength of theeyebar end connections vary due to geometrical differences. Therefore, the geometry ofthe eyebar should be analyzed to determine any points of higher stress that might inducefatigue cracking. These stress concentrations are typically found in the eyebar at the pinhole and the fillet where the eye head meets the shank.In the testing completed for this study, an analysis of the resulting stress found inthe eyebar connection from the Bell Ford Bridge under elastic loading was completed.The resulting stress distribution, of the eyebar connections showed that very high stressconcentrations were located on the outside of the pin hole. This suggests that crackingmight develop in this area under cyclic loading and lead to failure of the connectiondetail.