Finite element simulation of unbonded retrofitting system for a steel bridge in Australia

Pre-stressed unbonded retrofit (PUR) CFRP strengthening of steel structures is becoming a common method of strengthening metallic structures. This paper presents a comprehensive study on the use of the PUR CFRP-strengthening method for strengthening a steel bridge in Melbourne, Australia. Finite element analysis is performed in this study to model the entire bridge and the strengthened element, and the model is validated using actual on-site measurements which showed the stress developments of two girders before and after strengthening when a fully loaded truck passed over the bridge. A parametric study is performed to investigate the stress development of steel girders strengthened with the PUR system under different girder-deck levels of rigidity. The results showed a perfect match between the finite element modelling and actual measurements, and the effectiveness of the PUR system under critical conditions such as different girder-deck stiffness connection levels.