Parametric Studies and Preliminary Design Recommendations on the Use of Postinstalled Shear Connectors for Strengthening Noncomposite Steel Bridges

Abstract

This paper is a continuation of research on strengthening the load-carrying capacity of existing noncomposite bridge girders by postinstalling shear connectors. In this study, finite element models were developed to evaluate the behavior of composite beams retrofitted with postinstalled shear connectors over a wide range of variables with an objective of providing preliminary design recommendations. Variables considered in the parametric studies included beam depth, span length, and shear-connection ratio. The parametric studies showed that current simplified design approaches commonly used for partially composite beams in buildings provide good predictions of the strength and stiffness of partially composite bridge girders strengthened using postinstalled shear connectors. Use of a shear-connection ratio of less than 30% is not recommended to avoid nonductile behavior of the strengthened girder.