VSH Turòa nad Bodvou - Nemetschek Scia

Analysis of the Atrium Steel Structure
General Designer: STRABAG a.s.
Author of Design: RFR Paris, Jean Lelay
Structural engineer: PARS Building s.r.o. ing. Jaromír Tomek
Workshop documentation: PARS building s.r.o. ing. Jaromír
Tomek
Reviewer: Ing. Adolf Godík (BUREAU VERITAS)
According to the orders of the general designer, this document
contains a comparison of the authors’ design of the Atrium steel
structure with realisation of the documentation by the structural
engineer.
Basic data
The following data and documents were used for the comparative
stress analysis:
• Stress analysis - PARS Building
• Workshop documentation - PARS Building
• Design documentation - RFR Paris – Fragments without static
calculation
Used resources
FEM stress analysis software: ESA Prima Win 3.40.04
Spreadsheet program: Microsoft Excel
Used codes
DIN 18 800 Design of steel structure
DIN 1055 Loads
The elastic check was made according to T1 article 750. The limit
for the torsional check was 0,1. All sectional characteristics of all
general sections were calculated with FEM analysis.
Structure description
The steel structure consists of truss lift columns as a grand load
bearing structure, which is dominant for all vertical members. The
roof is made with a system of rods, tube columns and T-beams,
which form the bearing structure of the roof and facade glazing.
Steel structures compose the southern atrium of the building.
All possible temperature changes are taken into account. The
anchorage of the system is especially designed to reduce the forces
coming from this changes.
Structural stress analysis
This calculation was done as a 3D analysis with loads fully based on
DIN 1055. The software calculates all possible combinations and
adds together the appropriate maximums with the appropriate
combination factors. Only an exemplar part of the structure was
printed for this review as a representative extract.
Analysis tasks
The first task is to model and evaluate two different designs, the
second task is to compare the results, advantages and handicaps.
Evaluation
1. RFR - Paris Structure - T-beams with one brace
According to our analysis this structure is insufficient. See the
members with red area of sections efficiency.
The first basic handicap of the structure is sections insufficiency
between ca 1,2 to ca 3,7.
The second handicap – T- beams with only one brace is the
static system with tendency of infinity growing deformations in
case of insufficient torsion rigidity of the supporting beam (in
this case a triangle beam with insolvable torsion)
The third handicap – torsion of the triangle beams – there is
an absence of theory, we have no possibility to make correct
physical or engineering calculations to solve this problem and
make the structure infallible.
The fourth handicap – buckling of the lower strips of the triangle
beams is an unsolvable problem.
This structure cannot be realised without additional comments.
2. PARS - Building Structure - T-beams with two braces
According to our second analysis the structure is in limit or
slightly over. Additional second braces eliminate the torsions’
problem and assure the stability of the T- beam cantilever.
Buckling of the lower strips of triangle beams remains only on
the primary beams.
According to this calculation, the infallibility of this system is
sufficient. Reserves in critical parts of beams are still very small
and the stress in some parts of beams is in area of material plasticity.
It could cause growing deformations. Such structures
could be too sensitive to many different small accidents as a fire
and dynamic accidents etc.
All analysis details and more/all information are in electronic
form and it is possible to make complementary documents.
Conclusion
Such an important structure with great impact on a public area
with high traffic has to be systematically constructed with more
attention to safety, taking financial demands into account.
River City Prague
The project concerns an atrium in the city of Prague. The steel structure consists of truss lift
columns as a grand load bearing structure, which is dominant for all vertical members. The
roof is made with a system of rods, tube columns and T-beams, which form the bearing
structure of the roof and facade glazing. Steel structures compose the southern atrium of
the building. All possible temperature changes are taken into account. The anchorage of the
system is especially designed to reduce the forces coming from these changes.
River City Prague
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