From Point Cloud to HBIM to FEA, the Case of a Vernacular Architecture

The preservation of architectural heritage represents a major asset for economic development in several countries. Nevertheless, its protection remains a complex task due to its high vulnerability, especially in seismic zones.The intervention on the historical buildings requires the creation of a numerical and digital support shared by the different building specialists (architects, conservators, engineers, designers), which can contain all of the data relating to the construction. This will allow to ensure not only a better interchangeability between the different disciplines but also a correct and coherent conception and execution of the interventions.The introduction of 3D digitization tools, particularly the 3D laser scanner, plays a major role during the realization of the architectural survey. Indeed, the use of the architectural modeling software based on Building Information Modeling and Non-Uniform Rational Basis Spline allows first of all to move from the point cloud to an accurate 3D numerical model exploitable for various types of analysis, such as structural analysis, building archeology analysis, and thermal analysis.We propose through this article an unprecedented application of the 3D laser scanner on an example of vernacular architecture, constituting a truly unique type of "Medina." The object of the study is an aggregate composed of five houses, falling inside the Kasbah of Algiers, which since 1992 has been classified as "universal heritage" by UNESCO.The architectural survey is followed by a demonstration of numerical modelling based on 10 grades of generation using two categories of software founded mainly on Building Information Modeling and Non-Uniform Rational Basis Spline. Two kinds of numerical models are obtained: a first architectural model will be exploited during the building archaeology principally based on the 3D scanning results and a second structural model that will be used for structural analysis through a Finite Element Analysis software.