EXPERIMENTAL ASSESSMENT OF EXISTING BRIDGE STRUCTURE

Assessing existing bridges is an important task in the sustainable management of infrastructure, particularly for those structures that have been in service for extended periods and lack comprehensive technical documentation. In fact, due to the old age of a large part of the infrastructure assets and the deteriorating conditions affecting the structural elements, their safety with respect to the ultimate limit states may be compromised, making it essential to conduct experimental assessments and additional analyses to accurately determine their current load-bearing capacity and functional viability. Experimental tests performed on an existing concrete bridge built in the 90s are presented in this paper. The bridge is a single-bay structure with a simply supported beam structural system and a 12.8-meter span. The testing process was divided into two phases. In the first phase, the dynamic characteristics of the bridges were evaluated using the ambient vibration method, while the second phase focused on assessing the bridges' behavior under static and dynamic loads. More in detail, the second phase was carried out through load testing. To measure dynamic characteristics, accelerometers, data acquisition systems, and a PC were employed, whereas strain gauges, accelerometers, and linear potentiometers were used for static and dynamic loading tests. The results from these experimental tests can be utilized to calibrate and enhance the accuracy of numerical analyses for the bridges, so more complex analyses could be performed. Following the comprehensive analyses and investigations, conclusions were reached regarding the condition of the bridge structure.