Failure Analysis of Dapped-End Cracking in Posttensioned Bridge Girder

Abstract

This paper will examine in detail a posttensioned concrete (PTC) girder bridge with dapped-end connections, with a re-entrant corner diagonal crack that is typical of these types of bridges. This paper aims to identify the possible causes of the existing damage and the potential modes of failure of the bridge's girder using nonlinear finite-element analysis (FEA). Failure analysis of the bridge girder will consider the effects of supplying the bridge with different dapped reinforcements and subjecting the bridge's prestressed tendons to losses in their prestressing forces. Various failure scenarios and cases will be simulated in numerical models. Numerical analysis results will be compared with design guidelines for bridge girders. Overall, the investigative results indicated that the combined impacts of insufficient hanger reinforcement and prestress losses in the girder's end-section was the probable cause of the bridge's re-entrant corner diagonal crack.