Shear force transfer efficiency of tapered bridges with trapezoidal corrugated steel webs

Abstract

This study investigated the shear force transfer mechanism in a prestressed concrete (PC) tapered box girder bridge with trapezoidal corrugated steel webs (TCSWs) throughout the cantilever construction process by theoretical analysis, experimental verification, and finite element (FE) simulation. It has been determined that the assumption made in the current standards that TCSWs completely bear the shear force is inaccurate when designing tapered girders with TCSWs. The bending moment can cause a redistribution of shear force in a tapered case, which leads to the transfer of shear force from the TCSWs to the curved bottom flanges, resulting in the TCSWs and curved bottom flanges resisting shear force together. This study also reveals the shear force transfer efficiency in the maximum cantilever stage of the bridge. The results indicate that the shear bearing mechanism of the girder undergoes a gradual transition from a state where TCSWs are the primary shear resisting member at the section near the free end to a state where both TCSWs and the curved bottom flange collaborate to resist shear force as the section moves towards the pier. The study suggested that the maximum shear bearing ratio of the curved concrete bottom flange can reach 60.55% at the section near the pier, starting to replace the TCSWs as the main shear bearing member. Consequently, the shear force calculation method recommended by the existing standards may result in substantial computational errors, with the maximum error reaching as high as 155.62%.