Knies Magician's Hat in Rapperswil, Switzerland
The Knies Magician's Hat is the 2021 highlight of the reopened "Knies Kinderzoo" (personal petting zoo experience for children) in Rapperswil on Lake Zurich, Switzerland. The impressive shell structure was built using timber elements and rises to a height of 85 ft.
Gebrüder Knie Schweizer National Circus AG
Carlos Martinez Architekten
Ghisleni Partner AG
|Structural Engineering, Building Physics and Fire Design||
PIRMIN JUNG Schweiz AG
The new building in the children's zoo of the Knie Circus in Rapperswil brings a breath of fresh air to the site. The former sea lion arena has become obsolete, creating space for an event hall for concerts, banquets, events, and circus performances. The new building is impressive due to its unique architecture.
Dlubal customer PIRMIN JUNG was responsible for the structural design, structural design checks, and fire protection. They utilized RSTAB for the structural analysis and design.
The folded timber structure, designed by PIRMIN JUNG structural engineers, is held together by timber compression rings at heights of 36 and 59 ft and a concrete ring at the bottom. The compression rings give the roof structure a high degree of stability. Under the roof is the circus arena with a diameter of 104 ft, with a free span.
The structure is rotationally symmetrical and consists of twelve equal and twelve mirrored timber elements, each curved twice. Two of each element make a pair that forms one of the twelve V-shaped roof elements. They rest on the concrete tension ring at the low points of the collar roof. The "hat" forms the upper end of the roof structure.
The ribs and transverse ribs are made of glued laminated timber. On top of this lies a double diagonal formwork made of local spruce, which is 0.94 in. thick and bent and nailed manually. The roof elements, including the roof sheathing and shingles, were prefabricated from galvanized sheet metal at the factory. As a result, they weighed up to four tons; the "hat" itself weighed almost 20 tons. Due to the high level of prefabrication, the assembly time on the construction site could be kept short. Thus, the noise pollution to residents and the animals in the Knies children's zoo was reduced to a minimum.
Project LocationKnies Children's Zoo
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Compared to the RF‑/TIMBER Pro add-on module (RFEM 5 / RSTAB 8), the following new features have been added to the Timber Design add-on for RFEM 6 / RSTAB 9:
- In addition to Eurocode 5, other international standards are integrated (SIA 265, ANSI/AWC NDS, CSA 086, GB 50005)
- Design of compression perpendicular to grain (support pressure)
- Implementation of eigenvalue solver for determining the critical moment for lateral-torsional buckling (EC 5 only)
- Definition of different effective lengths for design at normal temperature and fire resistance design
- Evaluation of stresses via unit stresses (FEA)
- Optimized stability analyses for tapered members
- Unification of the materials for all national annexes (only one "EN" standard is now available in the material library for a better overview)
- Display of cross-section weakenings directly in the rendering
- Output of the used design check formulas (including a reference to the used equation from the standard)
- How can I neglect torsion in the steel and timber design?
- How do I perform stability analysis to determine the critical load factor in RFEM 6?
- Where can I find the materials for the corresponding National Annexes in RFEM 6 and RSTAB 9?
- How does the "Orthotropic Plastic" material model work in RFEM?
- What is the meaning of the superposition according to the CQC rule in a dynamic analysis??
- Can I use RFEM to calculate a log house three-dimensionally?
- How do I display some results of all load cases in the printout report, but other results of the selected load cases only?
- I would like to carry out the flexural buckling design for timber components with imperfections and internal forces according to the second-order analysis. Is it sufficient to activate this in Details of the RF‑/TIMBER Pro add-on module or is it necessary to make additional settings?
- Can I design laminated veneer lumber with RFEM/RSTAB?
- How can I calculate a timber-concrete composite floor with cross-laminated timber?