PSI - Issue 44

Dora Foti et al. / Procedia Structural Integrity 44 (2023) 1506–1513 D. Foti et al./ Structu al Integrity Procedia 00 (2022) 0 0 – 000

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Fig. 8. 3D view of the bridge AutoCAD model

Fig. 9 shows the different stages of construction of the 3D geometric model. With a thickness of 40 cm, the structural part (the shell), colored in yellow, was created by extruding all the faces of the geometric conformation in poly-lines (Fig. 8). The infill materials, colored in brown, were obtained as subtraction of solids.

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(c) Fig. 9. 3D view of the AutoCAD bridge solid model: (a) piers, abutments, arches, holes, bridge deck; (b) infill material; (c) complete model. This model was exported in .dxf format to be then imported into SAP2000 software, to create a finite element model. 5. Conclusions and future study The knowledge of the historical evolution, geometry and mechanical properties of the materials is often a crucial point for the structural analysis of bridges that require an accurate model for the quantification of structural vulnerability. Indeed, this type of construction is typically characterized by its high complexity in terms of size, location and internal composition. In this framework, the present study on the Santa Teresa Bridge proposes a methodology for realization of the geometric model of the structure to be investigated that starts from a survey and high-resolution images. This methodology is a first attempt to automate steps to be able to import more easily a complete and sufficiently detailed survey, which can take into consideration the peculiarities of a historical masonry arch bridges at different levels (geometric level, material level, structural system level). The procedure will be based on various experimental activities including the historical research, geometric characterization of ancient historical structures, which often presents drawbacks related to complex geometries and inaccessible sites, digital photogrammetric based on high-resolution images provided by UAVs was used to overcome these difficulties and to obtain accurate three-dimensional models from point clouds and at the end a special export instructions, in order to obtain a realistic and reliable geometric model (3D drawing) to import in structural softwares. Subsequent steps involve in situ monitoring and dynamic identification of the bridge, also considering that the overall structure is slightly skewed. In fact, the axes of the piers are not exactly perpendicular to the longitudinal