An analytical and experimental study of the bending stresses in the tie girder of a tied arch bridge.

An analytical and experimental study of the Unit II tied arch span of the 124 bridge over the Ohio River is presented herein. A finite element study was carried out to determine the live load stress response of the tie girder at a spliced panel point. Stresses were studied at locations at various distances from the spliced panel point. i A comparison was made between the analytical study and field study results, to determine the validity of the analytical model. The comparison does not provide for all the differences in the response. The study of stresses at various locations on tie girders showed that bending was a significant mode of response. Bending stresses made a predominant contribution to the stress cycles experienced by the tie girder flanges. The study also showed that the bending response was primarily a .localized effect. The presence of bending in the tie girder cannot be ignored. A modification of current design philosophy is required to account for the bending of the tie girder. Based on the stress history measurements in the field, an effective stress range was determined for the box corner weld detail. Fatigue life estimates were developed for various crack sizes.