PSI - Issue 44

Leonardo Cipriani et al. / Procedia Structural Integrity 44 (2023) 2106–2113 L. Cipriani et al. / Structural Integrity Procedia 00 (2022) 000 – 000

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The results of this preliminary experimental campaign (Table 1) gave a first knowledge of the behaviour of the structure and allowed to optimize both the sensor layout. (Fig. 2), reports the location and typology of the sensors chosen after the optimization of the monitoring system: (i) four uniaxial high sensitivity accelerometers (PCB model 393B31) in the internal middle sides of the quadriporticus; (ii) three uniaxial high sensitivity accelerometers (PCB model 393A03) in the middle of the tie roads across the vaults; (iii) two triplets of displacement transducers (Gefran PZ67-A) across the cracks in the cross vaults (for further details about the configuration of the displacement transducers, refers to Cipriani et al. 2021); (iv) two wireless sensors for internal temperature and relative humidity (Elitech RC-51H); (v) a weather station for temperature, relative humidity, wind speed and direction (WatchDog 2700) located in a balcony at the first floor.

vaults monitored through LVDTs

Fig. 2 Type of sensors and related configuration used in the Monitoring System.

Table 1 Results about the AVT ambient vibration testing.

Mode

Method

Frequency [Hz]

Damping ratio [%]

MAC

Modal shape

1 st translation in X

SSI/Cov

3.36 Hz

1.86 %

100 %

2 nd translation in Y

SSI/Cov

4.52 Hz

3.71 %

100 %

The acquisition procedure was developed in the cRIO 9045 using the programming environment National Instruments LabView to control the entire process. The initial configuration (October 2020 to May 2021) used a continuous data logging with a fixed time step of 30-minute time logging every 2 hours. Nevertheless, this configuration was not able to take the time history of a seismic event if it would happen close to the site but outside the recording-windows.