Structural and Design Details

1. HIGH RISE BUILDING
TAIPEI 101, TAIWAN
(Braced Core Structure)
Presented by:
Pranjal P. More
Maitreyee C. Joshi
Smt. Manoramabai Mundle
College Of Architecture, Nagpur

2. Overview
•Architectural Style: Postmodern (Pagoda)
• Architect: C.Y. Lee and Partners
• Construction Started: 1999
• Completed: 2004
• Type: Commercial Offices
• Height: 508 M (1,671 ft)
• Floor Count: 101 and 5 Below Ground
• Floor Area: 412,500 sq.m
• Lifts/ Elevators: 61
• Materials: Glass and Steel
• Taipei will remain strong in the situations
like earthquakes likely to occur in a 2,500
year cycle.
• It can also bare overall and localised load
effects from frequent and extreme
typhoones.

3. Challenges Faced
Taipei being a coastal city the problems present are:
•Weak soil conditions (The structures tend to sink).
•Typhoon winds (High lateral displacement tends to
topple structures).
•Large potential earthquakes (Generates shear
forces).

4. General Description
• Rising from dramatic,
landmark quality retail mall, the
tower has a profile unlike that
of any previous skyscrapers:
A tapering base topped by a
series of flared segments.
Typical setback floor plan shows saw
tooth corners, a braced core with 16
steel box columns, outriggers to 8
perimeter concrete filled steel box
super columns, upper (inner) and
lower(outer) perimeter wide flange
movement frame columns and in
floor bracing to transfer story shear
between modules

5. Structural Description
Foundation:
• Soft Rock occurs beneath 40-60m of clay and stiff colluvial soil.
• The design required a 21m deep basement, while ground water
is usually 2m below grade and potentially at grade.
• Five major components were used to create two different
foundation system.
 Slurry wall 1.2m thick surrounds both tower and podium; Its
47m depth cuts of ground water and provides toe embedment
well below the 21.8m -23.5m excavation depth.
 Each podium column bears on a single 2m diameter drilled
pier.
 Sockets 5-28m into bedrock resist net uplift from a podium
pressure slab resisting buoyancy.
 The single pier design permitted top down basement
construction: A floor was casted to brace perimeter walls, then
a story of excavation proceeded below it.

6.  Super structure framing was erected at the same time as a
result the retail podium opened about a year before the
tower topped out.

7.  Second slurry wall enclosing just the
tower footprint, was supported by steel
cross- lot bracing as excavation
proceeded to full depth.
 The walls were braced to
accommodate construction sequencing.
 A continuous reinforced concrete mat
3-4.7m thick transfers load from discrete
column and shear wall load points to
distributed pattern of 380 drilled piers,
1.5m in diameter, spaced 4m on centre in
staggered rows to resist gravity loads
between 10.7 and 14.2MN
 Using steel framing minimise building
weight, helping to reduce foundation cost.

8. Floor Slab:
 Slabs are composite in nature and are typically 13.5 cm thick.
Core :
 Within the core, sixteen columns are located at the crossing
points of four lines of bracing in each direction.

9. Column System:
 Gravity loads are carried vertically by a
variety of columns.
 Within the core, sixteen columns are located
at the crossing points of four lines of bracing in
each direction.
 The columns are box sections constructed of
steel plates, filled with concrete for added
strength as well as stiffness till the 62nd floor.
 On the perimeter, up to the 26th floor, each
of the four building faces has two ‘super
columns,’ two ‘sub-super-columns,’ and two
corner columns.
 Each face of the perimeter above the 26th
floor has the two ‘super-columns’ continue
upward.
 The ‘super-columns’ and ‘sub-super-
columns’ are steel box sections, filled with

10. Design to bare lateral loads
• The most of the lateral loads will be resisted by a
combination of braced cores, cantilevers from the core to the
perimeter, the super columns and the Special moment
resisting frame (SMRF).
• The cantilevers (horizontal trussed from the core to the
perimeter) occur at 11 levels in the structure. 5 of them are
double storey high and the rest single storey.
•16 of these members occur on each of such floors.
•The balance of perimeter framing is a sloping Special
Moment Resisting Frame (SMRF), a rigidly-connected grid of
stiff beams and H shape columns which follows the tower’s
exterior wall slope down each 8 story module.
•At each setback level, gravity load is transferred to ‘super-
columns’ through a story-high diagonali zed truss in the plane
of the SMRF.

11. •Above the 26th floor, only two exterior super-columns continue
to rise up to the 91st floor, so the SMRF consists of 600 mm
deep steel wide flange beams and columns, with columns sized
to be significantly stronger than beams for stability in the event
of beam yielding.
•Each 7-story of SMRF is carried by a story-high truss to transfer
gravity and cantilever forces to the super-columns, and to handle
the greater story stiffness of the core at cantilever floors.
•For additional core stiffness,
the lowest floors from
basement to the 8th floor have
concrete shear walls cast
between core columns in
addition to diagonal braces.

12. Wind Forces
• Skyscrapers experience alternating cross wind forces due to
vortex shedding.
• Resonance
•Here a typhoon with 100 years return period brings winds of
43.3m/sec (97 mph), averaged over 10 min at a height of 10M.
• Square tower with sharp corners creates large cross wind
excitation.
• Saw tooth or double notch corner with 2.5m notches achieved
dramatic reduction in cross wind excitation.

13. Construction Process
• 380 piles with 3 inch concrete slab.
Mega columns- 8 cm thick steel &
10,000 psi concrete infill to provide
for overturning.
•Walls - 5 & 7 degree slope.
106,000 tons of steel, grade 60- 25%
stronger.
•6 cranes on site – steel placement.
•Electrical & Mechanical.
•Curtain wall placement.

14. Damping System
•The main objective of such a system is to supplement the
structures damping to dissipate energy and to control undesired
structural vibrations.
•A common approach is to add friction or viscous damping to the
joints of the buildings to stabilize the structural vibration.
•A large number of dampers may be needed in order to achieve
effective damping when the movements of the joints are not
sufficient to contribute to energy absorption.

15. Energy Sink Damping System
•These are one of the latest damping systems available - called
Tuned Mass Damper.
•These take excess energy away from the primary structure.
• A TMD is a passive damping system, which consists of a spring, a
viscous damping device, and a secondary mass attached to the
vibrating structure.
•By varying the characteristics of the TMD system, an opportunity is
given to control the vibration of the primary structure and to
dissipate energy in the viscous element of the TMD.

16. TMD Used in Taipei 101
•The Taipei 101 uses a 800 ton TMD which occupy 5 of its upper
floors (87 – 91).
•The ball is assembled on site in layers of 12.5-cm-thick steel
plate. It is welded to a steel cradle suspended from level 92 by 3”
cables, in 4 sets of 2 each.
•Eight primary hydraulic pistons, each about 2 m long, grip the
cradle to dissipate dynamic energy as heat.
•A roughly 60-cm-dia pin projecting from the underside of the ball
limits its movement to about 1 m even during times of the
strongest lateral forces.
The 60m high spire at the top has 2 smaller ‘flat’ dampers to
support it.

17. THANK YOU