74
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Category 1: Buildings
Project Description
The Taiwan Tower in Taichung City, Taiwan, is a
direct result of the Taiwan Tower International Design
Competition. The project guidelines included a
construction budget of $220 million, as well as specific
required architectural features, such as a base level
city museum and observation decks, a restaurant and
an environmental monitoring station at the top levels.
In addition, the tower was required to be the tallest
building in central Taiwan, with a minimum height
requirement of 300 m.
Primary Structural System
The primary structural system for the tower consists
of 4 steel framed tubes 7 m in diameter which spiral
around an 8 m circular concrete core. Each tube is
composed of round steel pipes in a diagrid pattern that
rotates around the core, completing a full 360 degrees
of rotation over 240 m of rise in elevation.
At both the top and base of the structure the 4 tubes
flare out to allow for occupied space. The base contains
5 occupied floors, while the top contains 7 occupied
floors. Both the top and bottom are designed using
composite slabs on a steel beam and girder system with
large spans which accommodate open areas below.
Lateral System
As a result of the building’s height, the lateral system
was required to resist typhoon level winds of
+499.2 kg/m
2
and -748.8 kg/m
2
at the top of the tower.
Under this lateral loading, the central concrete core
transfers forces to the exterior tubes through a series
of small outrigger trusses which are placed at a 12 m
vertical interval for the full height of the tower. These
outrigger trusses allow the structural system to utilize
the exterior tubes to their full potential under all loading
conditions and greatly increase the lateral stiffness of
the structure as compared to a core only system. The
torsion induced on the core was offset by a continuous
truss which connects the tubes to each other and allows
the four individual tubes to work as a single unit.
Foundation System
All vertical and lateral load resisting elements will
terminate at a mat slab on a drilled pier foundation
system.
Repetitive & Modular Design
Although in geometrical terms the tower is complex
and unusual, the majority of the structural system is
repetitive and designed to be modular. The spiraling
tubes are designed to be fabricated in 3- or 6-meter
sections, either on or off site and lifted into place. The
tower core lends itself to a common climbing form work
system. These characteristics allow for a more easily
constructed structure.
Design Approach & Scia Engineer
Because of the tight project schedule (completed
submission in 4 weeks) and the complexity of the
exposed steel structure, the design team chose to utilize
Scia Engineer. Scia Engineer’s flexibility in 3D modeling
allowed for the structure to be modeled, analyzed and
designed for gravity loads, seismic loads, including
dynamic analysis and winds loads, all within Scia
Engineer. After the model was optimized, it was then
exported to the architect via IFC (Industry Foundation
Class). Using this OpenBIM workflow enabled the
design team to create a unique and collaborative
3D workflow that integrated the architecture and
engineering. Ultimately, this workflow allowed the team
to manage design changes and work iteratively towards
the final design, while also abiding by the project’s tight
deadlines.
Taiwan Tower - Taichung City, Taiwan
Software: Scia Engineer
