Effect of Temporary Shoring Location on Horizontally Curved Steel I-Girder Bridges during Construction

Abstract

Temporary shoring supports are used in construction of horizontally curved bridges to help ensure that the final constructed geometry is maintained by mitigating excessive girder deformations. Limited guidance currently exists in available design specifications and guidelines with respect to optimal placement of shoring towers because the number and locations of these supports are often site specific. However, if preliminary information could be provided to bridge designers and constructors with respect to shoring tower placement as a function of global curved bridge parameters, such as number of spans and radius of curvature, the amount of time required to specifically locate and proportion the towers could be reduced. This research aimed to examine the effects of shoring tower positioning on curved bridge behavior at different stages of construction. Sequential analyses of multiple idealized double-span curved bridges with varying radii were conducted using nonlinear finite-element models and vertical deformations and rotations of the girders, and shoring tower reactions were compared for different shoring support locations and different erection sequences. On the basis of the results, optimal shoring locations were obtained for the curved girders at different construction stages.