Historic bridge modelling using laser scanning, ground penetrating radar and finite element methods in the context of structural dynamics

This paper presents a general methodology to evaluate a masonry structure, considering the fact that the geometry of the structure is complex and that material properties are unknown and cannot be directly assessed. A multidisciplinary approach is presented that integrates laser scanning, ground penetrating radar (GPR) and finite element analysis (FEM) in the documentation of a medieval masonry bridge. The complex geometry of the structure is prepared using the data collected by a laser scanner. Since the bridge internal construction is not well known, GPR techniques are used in the geometric survey to estimate its homogeneity or heterogeneity. The resulting information is used to properly define a finite element-based structural model, which is then used to model the structural behaviour of the bridge. Moreover, the sensitivity analysis of the influence of the variation of Young’s modulus as a significant material parameter on the dynamic response of the bridge is performed. The study shows that this methodology has significant importance, particularly in the evaluation of the state of historic structures where, using non-invasive methods such as laser scanning and GPR is more appropriate.