Single-Row Spherical Domes in Stereotomy Treatises

[EN] This article focuses on analysing and modelling geometrically a complex vault typology known as single-row spherical dome, which was defined in several classic stereotomy treatises. The peculiarity of this kind of dome is that all their stone pieces are different, since there is a helical directrix defining the upper and lower edges of the pieces. Different solutions will be compared and analysed, both from a graphical and a mathematical point of view, by describing the spatial helixes. The accuracy of the different methods described in the treatises for tracing the stone templates will be also tested. To conclude, some examples of virtual 3D modellings and 3D printed models will be exposed.