Cold Curving Steel Bridge Girders

Horizontally curved steel girders are extensively used in bridge construction. An overview on a new, innovative cold bending technique for curving steel girders, specifically developed to meet the tight construction tolerance requirements of the Miami, Florida, Metromover, is presented. The curving procedure used by the fabricator was retained and detailed analyses were developed to provide closed-form solutions relating loads to deformation for curving symmetrical, asymmetrical, stiffened, and unstiffened girders. This eliminates the trial-and-error nature of the operation in the steel shop. Limits are imposed on the maximum load and corresponding plastic strain to prevent damage. Numerical examples illustrate the application of the proposed method and suggestions for future work are made on how cold bending may be adapted for bridge use.