An Evaluation of the Use of Fracture Mechanics Techniques for the Design of Orthotropic Decks

Abstract

Although the use of fracture mechanics based techniques in the evaluation of fatigue resistance in civil engineering has expanded steadily, it’s application in the field of orthotropic bridge decks remains very small. This is remarkable, since especially orthotropic decks have numerous fatigue prone details, which could benefit from a fracture mechanics based approach, or alternatively from the hot spot stress method. Currently, all international design guidelines for orthotropic plated bridge deck are based on a traditional nominal stress S-N approach and Miner’s Rule, and, although suggested by various in field designers and bridge owners, a fracture mechanics approach is currently limited to academic research. The paper gives an overview of current practice in the field, as well as an overview of attempts made academic researchers to apply fracture mechanics techniques. The available literature suggests that the lack of implementation of fracture mechanics results from a combination of factors including the lack of experience with these methods, conservatism, but also the complexity of geometry and loading conditions resulting in numerous variables. This paper may contribute to the implementation of modern fracture mechanics based techniques in this field by pointing out the opportunities and warning for the difficulties.