The subject of this study is the assessment of the safety of the whole construction from a mechanical standpoint. The fundamental pathology of the building consists of the settling of part of the foundations, which has caused the rotation, breakage and cracking of the side walls, the breakage and slumping of the subarches, as well as the cracking in part of the tambour. A three-dimensional model of the building is made by the Finite Elements method, with a mesh of solids for the walls, pilasters, subarches and tambour, along with a surface element mesh for the dome.