On the benefits of the use of complementary numerical models for the structural analysis of a historic masonry monument: Application to a sexpartite vault of Notre-Dame de Paris cathedral

The preservation of a historic masonry monument with structural pathologies requires the implementation of a multidisciplinary diagnostic approach including a mechanical assessment of the structure. To this end, a wide variety of models (such as Continuum Homogeneous Models (CHM), Block-Based Models (BBM) and geometry- based models (GBM)) are available in the literature to simulate the mechanical behavior of this type of structure. In this article, three different models (two BBM and one CHM) are used simultaneously to assess the structural behavior of a choir span of Notre-Dame de Paris Cathedral in Paris, with an aim to assist architects with diagnosis and repair operations within a time frame of approximately one year. The same set of assumptions (loading, geometry, mechanical parameters) was applied to all three models. Using these models simultaneously allowed the research team to build an optimized structural assessment based on constant interaction between the different modeling approaches. This enabled the team to leverage the strengths of each method, ensuring a high degree of confidence in the final results. The comparison of models also revealed potential improvements that could be made to each model, with the goal of reducing calculation times and/or enhancing the consistency of results, particularly in terms of failure mechanisms and behavior laws.