Inspirations in Engineering 2013 - page 24

Category 1: Buildings
Software: Scia Engineer
The Groninger Forum is a 35,000 m
conference building located in the heart of the city of
Groningen, just a few metres from the famous Martini
Tower. Commissioned by the municipality of Groningen,
NL Architects Amsterdam designed a spectacular
building in which the freely accessible 40 m-high atrium
provides a spectacular view over the city. The contour of
the superstructure is characterised by the various wall
surfaces extending obliquely in a forward or backward
tilt. From this contour a ‘keyhole to the city’ that forms the
atrium is achieved.
Located around the atrium, the Groninger Forum has
‘volumes’ housing five cinemas for film or debates, a
‘public demand’ cineac, training rooms, an auditorium
annex theatre and various exhibition halls. Through the
20 m-long atrium, free span escalators transport the
visitors, amid projections and presentations, to the indoor
plazas. All the plazas located on 10 different levels, also
facilitate exhibitions and presentations. In addition, the
Forum houses two open stages, workstations for students
and self-employed people, a grand café, a movie café,
a restaurant on the top floor, a roof cinema and a library.
The substructure houses a 5-storey parking garage and a
single-storey bicycle parking facility.
ABT involvement
ABT is involved in feasibility studies of the plan, structural
design, architectural plan development, construction
management, project management and supervision,
geotechnical consultancy, BIM coordination, design
management and construction logistics plans.
Structural solution - unique features
The extreme oppositional oblique structure can be
divided into two sections: super- and substructure. The
superstructure consists of 11 floors, the substructure of
a 5-layer parking garage containing approximately 400
parking spaces and 1,200 bike stable places. The gross
floor area of the project is 20,300 m
(cultural complex)
and 14,500 m
The two concrete cores on the west and east side are the
main stabilising parts of the building. The steel volumes,
constructed from oblique trusses, are connected to these
cores. At levels 9 and 10 a steel bridge connects the two
cores. In order to limit the span of the volume cantilevers,
additional vertical load-bearing lines (columns) are
applied. Just one of the challenging ambitions of NL
Architects: the columns may not be positioned in one
vertical line, at any level. The trusses have different
inclinations and the position of the vertical bearing
elements is irregular in all directions. All floors have
horizontal bracings in order to compensate for the oblique
position of trusses.
Unique for the steel trusses is that the top line of the
trusses can slide at the top line until the building is
complete. This prevents additional forces, partially caused
by translating of the concrete core, negatively influence
the steel structure.
The parking garage consists of concrete floors, walls and
columns. The outer walls of the bicycle parking facility
consist of traditional concrete walls. The deep basement
diaphragm wall panels have the thickness of 1.0 to 1.2 m.
The floors of the garage give, in addition to the vertical
traffic loads, horizontal support to the outer walls because
of the elongated void in the middle. In order to optimise
the construction process, an underwater concrete floor
(thickness: 1.0 m) is made. All floors are made of steel
fibre reinforced concrete.
Scia Engineer
From an engineering point of view, the Groninger Forum
is a very complex structure. During the development ABT
uses Scia Engineer for all engineering challenges. In the
preliminary stages, for 2D analysis of trusses and floors.
Later on, in the process for 3D analysis, detailed analysis
of 2nd order, stability and stiffness, of sub-sections of
the building. Finally, the sub-models are merged into one
overall model.
This working method has resulted in an essential and
exact understanding of the behaviour of the building and
also given direction to the assembly plan.
The complexity of the building shape also has an effect on
building the FEM models. Connecting the sloping floors
and oblique facades demands a very precise model to
ensure accurate results. Also, the aligning and connecting
elements in transition areas required the necessary care.
Due to the interface of Scia Engineer, quick and steady
editing of the geometry can easily be done.
Groninger Forum - Groningen, The Netherlands
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