Automated Voxel Model From Point Clouds for Structural Analysis of Cultural Heritage

Abstract

ABSTRACT:In the context of cultural heritage, an accurate and comprehensive digital survey of a historical building is today essential in order to measure its geometry in detail for documentation or restoration purposes, for supporting special studies regarding materials and constructive characteristics, and finally for structural analysis. Some proven geomatic techniques, such as photogrammetry and terrestrial laser scanning, are increasingly used to survey buildings with different complexity and dimensions; one typical product is in form of point clouds. We developed a semi-automatic procedure to convert point clouds, acquired from laserscan or digital photogrammetry, to a filled volume model of the whole structure. The filled volume model, in a voxel format, can be useful for further analysis and also for the generation of a Finite Element Model (FEM) of the surveyed building. In this paper a new approach is presented with the aim to decrease operator intervention in the workflow and obtain a better description of the structure. In order to achieve this result a voxel model with variable resolution is produced. Different parameters are compared and different steps of the procedure are tested and validated in the case study of the North tower of the San Felice sul Panaro Fortress, a monumental historical building located in San Felice sul Panaro (Modena, Italy) that was hit by an earthquake in 2012.

Bim for Museums: An Integrated Approach From the Building to the Collections

“…Two main inputs are needed to build reliably and consistently a FE Model: i) the mesh and ii) the additional information to be implemented within the finite elements (properties, loads, boundary conditions etc.). The mesh can be obtained from a geometrical input of topological content, such as a combination of primitive forms, or producing this content directly from other sources, such as terrestrial laser scanning (TLS), based on cloud points outputs (Bitelli et al, 2016;Castellazzi et al, 2017;Korumaz et al, 2017). The former procedure is more compatible inside a BIM or H-BIM context, where the availability of data, or data storing procedures, can help in improving the interoperability and easily retrieving information from the same databases.…”

Point Cloud Dataset and Fem for a Complex Geometry: The San Luzi Bell Tower Case Study

“…Of course, the analysis process directly depends on the accuracy of the measured data (Boehler et al, 2003;Bolognesi et al, 2014). With its high level of detail, TLS is very versatile and could be used, for example, in the assessment of building conditions (Tang and Akinci, 2012), computing accurate parametric models of complex objects (Bauer and Polthier, 2009), or taking advantage for the preservation of a building damaged from an earthquake (Bitelli et al, 2016;Brumana et al, 2018). With increasingly complex architectures, one of the key problems in civil engineering is the improvement of the reliability of the constructed structures.…”

Metric Documentation of Cultural Heritage: Research Directions From the Italian Gamher Project

“…Specific contributions will be provided especially in the integration and interface with FEM products, to be tested on selected historical buildings (see Fig. 3 for the example proposed in Bitelli et al, 2016, from the Bologna University research unit). Actually, current software tools for transforming surveying data into structural models, typically finite element ones, still suffer from the inability to capture potentially critical details and a high degree of human interaction.…”