Spiral Staircase with Glass Steps, Zlín, Czech Republic

Customer Project

The goal was to design a spiral staircase with glass steps and railings spanning over 2 floors. With sophisticated anchoring details and helical stringers created from subtle rectangular hollow section, a light and elegant staircase was formed. The interior spiral staircase is located inside of the educational, training and rehabilitation center in the city of Zlín.

Structural Analysis Ing. Vítězslav Hapl
Ing. Jan Mařík, Ph.D.
Ing. Jan Seifert
KONSTAT s.r.o.
Architectural Design CUBE DESIGN s.r.o.
Construction STAIRS design s.r.o.

Model Parameters



Looking 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 portion and the 2nd to 3rd floor portion. The staircase 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 by a suitable elastic material. The railing is considered only as a load and therefore has no load-bearing function.


Due to the above-mentioned staircase floor independence, only one part of the staircase is modeled. The stringers and anchor elements are modeled with plate elements, and the stair treads are modeled as members. To estimate the maximum glass step loading and to evaluate the steel stringer maximum loading, two different stiffness values were used for the glass step connection and the support cantilever. The restraint in the reinforced concrete slab is modeled with a nonlinear failure under tension, elastic support applied to the anchor element’s individual surfaces.

Project Location

Mladcová, Zlín


Steel stringers Glass steps RFEM

Write Comment...

Write Comment...

  • Views 168x
  • Updated 01/15/2021

Contact us

Do you have questions or need advice?
Contact our free e-mail, chat, or forum support or find various suggested solutions and useful tips on our FAQ page.

(267) 702-2815


RFEM Dynamic Analysis
RF-DYNAM Pro - Natural Vibrations  5.xx

Add-on Module

Dynamic analysis of natural frequencies and mode shapes of member, surface, and solid models

Price of First License
1,030.00 USD