The vaulting system of the Palatine Chapel: the Aachen Cathedral World Heritage Site documentation project

As part of a comprehensive survey and modelling project involving the Aachen Cathedral, this paper focuses on its oldest part, the Palatine Chapel, a domed octagonal hall supported by eight piers and enveloped by a sixteen-sided outer wall. Working on the data collected during an extensive 3D capturing campaign conducted between 2022 and 2023, this paper will focus on the conic vaults covering the ambulacrum of the 1st floor that represent quite a peculiar architectural and structural solution considering the VIII/IX century building know-how. In this framework, the Chapel's 3D point cloud has been analysed to extract the main 2D generative elements of the conic surfaces and then construct the corresponding 3D geometric models. These outputs have been compared against the captured point cloud to assess the differences between the actual vault data and the reconstructed ideal conic shapes. Finally, the method used to unfold the vaults' surfaces and create high-resolution ortho-images has been displayed.