3D AND HBIM MODELS: DIGITAL TOOLS FOR THE DIAGNOSTIC STUDY OF THE STAIR TURRET OF THE SOUTH-EAST CORNER OF THE MAIN TOWER OF STRASBOURG CATHEDRAL

Abstract. During the construction of Strasbourg Cathedral, men aspired to see it radiate eternally. However, like any monument, it experiences structural weakening due to the effects of time, but also to the many external aggressions that damage the materials. Regular interventions therefore make it possible to preserve this building over time. It is in this context of conservation that the cathedral lives to the rhythm of a major restoration campaign since 2014. The objective of this project was to carry out a modeling and a BIM model of the stair turret in the south-east corner of the main tower built entirely of sandstone. This work was part of the preparatory phase of the restoration work on the south-east stair turret of the high tower scheduled for 2024–2025. The objective was to carry out a diagnosis of the turret (35 m high, 168 steps) with the help of a 3D and BIM model. This study could be understood as the beginning of a more global work of 3D representation extendable to the entire monument. In addition, in the spirit of gathering information and building knowledge base, it could be interesting to develop a complete BIM model of the entire building later.