Stresses in Steel Curved Girder Bridges

Project summary:

Curved girder steel bridges are typically designed based on forces and stresses obtained from commercially available computer programs. The geometry of these structures precludes simple approaches in their design and thus the verification of the design forces and stresses generated by the program is generally not possible. Recently MnDOT has noted two problems in the design and construction of curved bridges: (a) problems due primarily to excessive deflections during erection, and (b) concern for the forces in the diaphragms under service loads. To help in assessing the accuracy of current design procedures, a curved steel bridge will be instrumented to determine the in-situ service stresses and deflections. The intent is to track the stresses through the fabrication, erection, construction and proof loading of the bridge. The field studies will be complemented by extensive, first-order computer analyses to correlate the stresses measured in the field with those obtained from both commercially available computer programs and a modified in-house computer program. This work will be fully coordinated with the FHWA research group on curved steel girders currently managed by HDR-Pittsburgh.