Abstract: A device has at least two longitudinal uprights (1, 2) each of which is made up of a series of juxtaposed aligned discrete sections of a given section member through which a throughway longitudinal cavity and grooves parallel to the cavity are defined. An elongate connecting device extends through the cavities of the sections and maintains them in alignment and assembled to one another. These uprights (1, 2) support transverse members (41) of an intermediate structure (30), the transverse members being engaged in the grooves of the sections. Fixing devices slidable in the grooves of the sections fix the transverse members (41) in position. Each upright may have rectilinear parts interconnected by at least one curvilinear part. The rectilinear parts consist of a single section of the section member while the curvilinear parts consist of a plurality of small sections (10a) of the section member having end faces that are convergent toward the center of radius of the desired curve.