VSH Turòa nad Bodvou - Nemetschek Scia

In General
The block of flats “OBYDICK” is planned to be erected in Bratislava.
The structural design for the building licence was elaborated by
ELTER Constructions s.r.o. of Slovakia. The detail structural design
was elaborated by Ing. Daniel Bukov OK TEAM .
Basic Parameters of the Building
The total number of floors is 25 above ground level and two floors
below ground level. The total height of the building is 85.27 m.
The total area is more than 21.000 m², that is more than 650 m²
per floor.
Main bearing system
The main bearing system of the building is created from cast instead
of reinforced concrete. In the middle of the building is located a
small core with the dimension 5.85 m x 12.5 m, the thickness of
the walls are 200 mm. Oval columns support perimeter concrete
walls. These walls create an outside tube. The tube transmits a big
portion of the horizontal loads. The outside wall has thicknesses
from 500 mm to 200 mm. The ground floor level has the thickness
of the wall: 500 mm. On the inside layout circle there are located
columns with diameter of 600 mm.
Method of Detail Designing
For the computation of the shape of the structure, cross sections,
thicknesses and loads were taken into account. New information
concerning the openings (location and dimension) were also
included in the structural analysis. For the calculation of the main
bearing system, the 3D model is created. For the separate parts, an
own model was created (floor slabs, columns, attic etc.). The results
from the global calculation are included into separate models as
external loads or are included in the proportioning. All calculations
are performed according to the Slovak valid codes.
Computational model
A 3D computational model, created by the finite element method,
calculates the main bearing system of the building. The foundation
slab, including soil interaction, core walls and columns, is exactly
modelled in this space model. Floor slabs are also modelled precisely,
but for computational reasons only a very large mesh is used. For
the seismic response, the calculation linear response spectra method
is used. For a combination of modal responses, the CQC method is
used. Soil interaction has been solved with the theory of half space.
The proportioning of the foundation slab and core walls is done in
this model without any other influence or consideration.
For columns proportioning from the global structural calculation,
only normal forces have been adopted. The bending moments
were added from floor slabs analysis. All calculations are performed
by NEXIS 32.60.20 program (ESA-Prima Win). For tall buildings it
is necessary to take into consideration the influence of the longi-
tudinal deformation of the columns on the main bearing system.
Deformations of columns due to high compression have to deal
with elastic deformation creeping and shrinkage of the concrete.
Floor slab levelling eliminates some deformation; some has to be
predicted by calculation. It is also necessary to take into the consideration
the decreasing normal forces in the columns due to the
decreasing effect of the live load depending on the number of the
floors above. Influence of the settlement in the core area, which is
higher than settlement in the perimeter columns, also plays a role
in the designing of the bearing system. For seismic response calculation,
different sub grade properties have to be used (stiffness or
resistance of the soil in the case of the dynamic loads is higher).
At least two models have to be calculated for one proportioning.
With ESA-Prima Win we have the possibility to make many calculations
in real time
Foundation Slab Design and Calculation
The internal force and the calculation of the foundation slab on
the 3D model for global structure analysis were used here. The
proportioning was performed in the same model.
Columns calculation
Calculation Columns are calculated in a separate calculation.
Normal forces are adopted from global structural analysis. Bending
moments are adopted from floor slab calculation. For each type of
column, a calculation is performed and influence due to live load is
taken into consideration.
Perimeter walls- tube calculation
The tubes are perforated by window openings. The critical parts of
the tube are those where they are connected to the columns. For
these parts a very fine mesh was used, also a separate calculation
of the detail was performed.
Floor Slab Calculation
Floor slabs are calculated in a separate model, punching shear and
connection to the core walls is taken into account. In this model
also bending moments in the columns are calculated. Around
the columns a more dense mesh is used. On one side, there are
decreased bending moments in the columns, and on the opposite
side, there are increased positive moments in the floor slab. The
proportioning of the slab in the columns is done based on sections
and the reinforcement is distributed accordingly.
Conclusion
In order to obtain a solution of such a demanding structure, a very
effective program for the calculation of internal forces calculation
is needed. It must be able to prepare the structural model and to
offer various possibilities to check the results. The incorporation
of the proportioning in one package is also a big advantage.
ESA-Prima Win fulfils these requirements.
High rise building
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