3. POINTS TO BE COVERED
• Details of project
• Ancient technology
• Foundation details
• Design criteria
• Vibration control system
• Safety measures
3
4. DETAILS OF PROJECT
• Project name – Tokyo Sky Tree
• Location – Sumida, Tokyo
• Height of project – 634m
• Purpose – Broadcasting tower, Restaurant
• Project duration – 4 years
• Project cost – $800 million
• Contractor – Obayashi Corp.
4
6. ANCIENT TECHNOLOGY
•Tokyo Sky tree has also adopted the ancient
building technologies of "curve" and "camber."
•"Camber," in which the central part of a pillar
in an ancient wooden building is slightly
bulged, and "curve," which can be seen in
Japanese swords, are both used in Tokyo Sky
tree.
6
7. FOUNDATION DETAILS
• Type of soil at site is silt.
• Hence RC wall pile type foundation is adopted to
counter the earthquake effects.
• Spikes like protuberances rise from walls to hold
soil firmly.
• This technique is called Knuckle Walls.
• Piles are driven 35m into the ground.
7
8. • Reinforced concrete walls connect these 3
points to form a complete triangular shape
driven 35m deep under the ground.
• Pile of length 2.3m and diameter of 10cm
were adopted.
• SRC pile system is adopted to have the
continuity of steel member.
• Maximum load was 40,000kN during pull-
out test
• Aspect ratio is about 9.0.
• Top displacement is too large if foundation
has poor vertical rigidity.
8
9. DESIGN CRITERIA
• Tower was designed to resist up to the
earthquake magnitude of 7.3
• The wind speeds at height of 600m were
measured using balloons.
• Winds are measured using ultrasonic wind
gauge for two years.
9
10. VIBRATION CONTROL
SYSTEM
• Two methods are used – Tuned Mass
Damper(TMD) and Core Column System
• To suppress the wind at top of tower 2 TMDs
are installed in the means of weights, springs,
dampers
• TMD weighing 40 tons are installed at 620m
height and TMD weighing 20 tons are installed at
625m height
10
11. • A core column was provided in the center of
structure.
• It is a cylindrical shaped column of reinforced
concrete.
• Diameter is 8 m and height of column is 375
m
• Above this height oil dampers are provided to
suppress the motions.
11
12. SAFETY MEASURES
• Providing waterproof canvas to workers to protect from wind
and dizzying.
• 2 safety lines are implemented instead of one to all the workers.
• 100 m steel protective panels are setup over the railway just
beneath the tower.
• Building huge steel scaffolding in ground and placing in
required position using cranes.
12
