Bridge abutment movement and approach settlement : a case study and scenario analysis

Movement of bridge abutment is a significant issue affecting the overall reliability and safety of the structure. However, despite considerable consequences, potential movement of abutment is usually not considered in design of bridges for serviceability and abutments are generally designed as fixed elements. Theoretical analysis of bridge abutment and deck design provides background knowledge of reactions that should be anticipated and accounted for. Case studies of bridges experiencing movements and rotations show that practical outcomes often deviate from theoretical expectations. The research presented in this paper, aims to develop a better understanding of abutment stability from both a design and maintenance point of view. This paper includes an in-depth case study of the Kanahooka Road Overbridge in New South Wales, Australia. The results of a full bridge inspection leading to identification of multiple serviceability issues caused by movement of abutments are presented. Moreover, a systematic methodology is implemented, to identify potential remedial options for treatment of abutment movement. The knowledge gained through this case study has led to the development of a model for the management of abutment movement.