Considerations for Opening New Access Holes in Curved Box Girders

Abstract

Access hatches (holes) in curved-box-girder bridges are usually provided in the bottom flange immediately before or after an expansion joint. If additional access hatches are required after the bridge is built, they must be placed in such a way that (1) they satisfy such important practical constraints as feasibility, accessibility, water leakage, traffic impact, and unauthorized access, and (2) they do not adversely affect the structural behavior of the bridge—i.e., their installation should not impair serviceability or decrease ultimate strength or fatigue life. This paper discusses both of these issues and proposes approaches that are suitable for identifying appropriate locations for access hole placement. The proposed approaches are used to investigate seven curved-box-girder bridges located in the state of Florida. One of the bridges is chosen for further study using a detailed finite-element model. The numerical model is used to confirm the proposed methods and to further investigate the effects of adding access holes.