PSI - Issue 78

Pasquale Guarino et al. / Procedia Structural Integrity 78 (2026) 1561–1568

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Fig. 2. Geometrical dimensions of Mikron Historical Arch Bridge: a) Plan view, b) A-A section

3. Case study

To evaluate the e ff ectiveness of the tool, a masonry arch bridge has been considered for model updating. The case study structure is the Mikron Historical Arch Bridge studied by Sevim et al. (2011), a single span arch bridge located in Rize, Turkey. Sevim et al. (2011) worked on the calibration of boundary conditions of a FEM od the bridge. This structure has been chosen testing the developed software plug-in. The structure is made of two side walls, a timber block, an inner arch, and an outer arch. A small restoration phase occurred on the bridge to enhance its structural integrity, leading to a decrease in the frequencies with an additional outer arch. The total length of the bridge is 33.80 m, and the depth is 3 m. After the restoration, the radius of the bridge is 10.60 m, and the total height is 11.60 m. The analytical model is shown in Fig. 2. The material properties of the side walls have been chosen for modal updating. For this purpose, two di ff erent models have been generated: 1. The first arch bridge, used as a benchmark, has the same material properties used by Sevim et al. (2011) for the reference solution. 2. The material properties of the side walls’ material of the second arch bridge were changed to simulate a wrong choice of material properties.

The material properties of both models are reported in Table 1.

Table 1. Mechanical properties adopted to specialize the structural response of the arch bridge in the numerical simulations Benchmark Altered model Materials E (MPa) ρ (kg / m3) υ E (MPa) ρ (kg / m3) υ Stone Arches 3.0E9 1600 0.25 3.0E9 1600 0.25 Timber Block 1.5E9 1300 0.05 1.5E9 1300 0.05 Stone Walls 2.5E9 1400 0.20 1.8E9 1100 0.20

Sensor positions, experimental frequencies, and mode shapes are needed to perform the model calibration. In this case study, the first four vibrational mode shapes were considered. The first arch bridge has been used to extract the experimental frequencies and mode shapes. The modal displacements of 12 sensor locations were extracted to