MODAL IDENTIFICATION AND FINITE ELEMENT MODEL UPDATING OF A REINFORCED CONCRETE

This paper summarizes the application of a rational methodology for the assessment of older reinforced concrete Tunisian bridges. This methodology is based on ambient vibration measurement of the bridge, identification of the structure’s modal signature and finite element model updating. The selected case study is the SidiBouAli river bridge which is an eight-span simply supported bridge with a continuous slab. Each span has a length of 25 m and is supported by rubber bearings at the supports. Ambient vibration tests with output-only measurements were conducted on the bridge using a data acquisition system with nine force-balance accelerometers placed at selected locations of the bridge. The Enhanced Frequency Domain Decomposition technique, known to be robust with respect to the complex non-stationary nature of the unmeasured excitation, was applied to extract the dynamic characteristics of the bridge. Fo