PSI - Issue 44

Rebecca Asso et al. / Procedia Structural Integrity 44 (2023) 894–901 Rebecca Asso et al./ Structural Integrity Procedia 00 (2022) 000–000

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On the other hand, the dynamic identification tests determine the natural frequencies, the shapes of modes of vibration and the damping value of the structures. These tests supplement the static ones. Testing is recently being boosted by data-driven analysis. SHM consents a rough assessment of structures due to the possibility of surveying the structures along a timeframe or further, its lifespan. In fact, the continuous stream of information is a newly developed skill in the structural engineering world that has to be expanded to its whole potential. Coupling SHM with testing allows marking the evolution of the structural response subjected to external changes. 1.2. Case study The case study is a prestressed concrete box girder on four supports, characterized by 3 spans of 38.6 m for the outers and 78 m for the central. The bridge is overpassing the Po River, and it was built in the 1970s.

Figure 1: Longitudinal section of the bridge.

Due to a degraded state of the steel supports found during an inspection, a monitoring strategy is set to indagate the causes of the possible outcomes of the impairment. As a function of the analysis of the data obtained from the sensors, the necessity of intervention is set, which includes lifting the carriageway, removing existing supports, and installing new elastomeric supports. The assessment of the substitution is conducted through a finite element model, developed in MIDAS Civil (MIDAS Information Technology Co. 2022), and coupling the model to the output obtained from the gathered data. The monitoring approach was installed as shown in Figure 2 and Figure 3.The strategy is categorized by: • a total of ten strain gauges for monitoring the structural deflection; • a total of two inclinometers for monitoring the deformation of the piles; • a total of four crack meters for monitoring the displacement of the supports. This article exposes the information from the latter.

Figure 2: Longitudinal section of the bridge with detail of the sensors.