Structure
From the structural point of view and excluding the rigidity of the reinforced concrete structure, the staircase can be separated into two parts – the 1st to 2nd floor section and the 2nd to 3rd floor section. The staircase's supporting structure consists of internal and external helical stringers. The stringers are fixed to the landings (welded to the pre-built anchor elements) and to the 1st-floor slab (anchored via Hilti adhesive anchors).
The stringers are made of welded closed hollow sections with recessed flanges. The upper flange recess creates a groove for mounting a glass railing, while the lower flange recess is purely an architectural element. The stair treads are made of laminated tempered glass.
The treads are attached to a cantilevered box section (1 inch wide x 1 inch deep), further welded to the stringer web at four locations. The glass tread is supported on the cantilevers by an elastic band and fastened with metric screws. Due to the rigidity of the step-stringer connection, the steps are considered in the computational model.
The inner and outer stringer railings are made of laminated tempered glass bent to the appropriate radius. The railing is inserted into the stringer groove, positioned by elastic spacers, and finally glued into the groove with a suitable elastic material. The railing is considered only as a load and therefore has no load-bearing function.