PSI - Issue 64

Filippo Andreose et al. / Procedia Structural Integrity 64 (2024) 40–47

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• Seismic analysis: here potential seismic events are detected providing alerts in case of exceedance of acceleration thresholds, evaluating different intensity measures and capturing real drift ratio demands acting on piers. • Structural reliability: evaluation of the reliability index can be carried out as a function of main deck features to get an estimate of the safety margin with respect to traffic loads. The analyzes mentioned previously are described in detail by Garcìa-Macìas et al. (2023). 3. Case studies and discussion This section illustrates the first preliminary results obtained from the SHM via P3P of three case studies belonging to the stock of 1000 bridges owned by ANAS to be monitored in the next years, showing the potentialities of the P3P software suite in handling huge amount of data and capturing potential anomalies. This is a three continuous span concrete-girder bridge 138 m long located in the Italian region of Lazio, along the A90 highway, in Rome municipality (Fig. 2). The spans are all different, with a maximum length of 50 m, and width of 19 m. Each span is made of nine longitudinal pre-stressed girders and connected to reinforced concrete deck slab. A dynamic monitoring system was installed on the bridge with the aim of testing it with P3P. The system comprised 21 MEMS-based accelerometers covering 27 measurement channels. Wind and traffic were the main sources of excitation for the structure. Some OMA modal analysis was performed using P3P software, starting from the data acquisition of monitoring system. FDD and SSI-cov was performed processing all the acceleration data channels. Fig. 3 shows the modal geometry (a), SSI-cov stabilization diagrams (b), some vibration modes (c) and the MAC diagram (d). 3.1. Ebrei ’s bridge

Fig. 2. Ebrei ’s bridge.

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(b)

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Fig. 3. Modal geometry (a), SSI-cov stabilization diagram (b), some vibration modes (c) and the MAC diagram (d).