Tall, breathtaking and absolutely stunning,
those are the words that entered my mind as I looked at the pictures and
watched the videos about Taipei 101. I was amazed not just because of its
physical beauty but also for the fact that Taiwan is one of the countries that
is prone to disasters, windy climate and even occasional earthquakes all year
round. If you are going to ask me how Taipei 101 we’re able to survive that
condition, all I can say is “I don’t know”. So, come and join me as I pondered
and searched for answers.
First, let us know some
challenges that Taipei 101 had overcome in the previous years. Every project
has a list of challenges and as for the Taipei 101, that list is very long.
Starting from its design height of 508 m, it also includes its overall and
localized effects ranging from frequent and extreme typhoons then potentially
severe earthquakes to a difficult subsurface condition, including an inactive
fault line through the site(Poon et.al, 2004).
According to Alex Zimmer(2014),”In the late 90s, Taipei 101’s structural engineer,
ThortonTomasetti, set out to construct the world’s tallest building in the one
of the world’s most uninviting cities for skyscrapers and his solution in this
unstable environment is an enormous, 700 ton ball, constructed out of steel,
that hangs like an uvula between the 87th and 92nd floors of the building.”
This ball of steel really helped a
lot in stabilizing the building. But, what is this ball of steel and how is
that ball of steel able to do all that?
The ball of steel is called the TMD
or what is known as the Tuned Mass Damper. It hangs like a gigantic pendulum
andacts as a massive counter balance which counteracts
any swaying, ensuring that the individual pieces of Taipei 101 will not
collapse as the daily winds whip around the building, or when strong winds or
earthquakes struck the building. It rests inside a sling made of steel cables
and has its own shock absorbers. The mass
damper is composed of 41 layers of 12.5 cm (5 inch) thick solid steel plates
stacked and riveted together to form a sphere that measures 5.5 m (18 feet) in
diameter with a weight of 660 tons.
The ball itself was assembled on the
site in layers of 12.5-cm-thick steel plate and is welded to a steel cradle
suspended from level 92 by 3″ cables, in 4 sets of 2 each which allows it to
havea maximum swaying amplitude of 150 cm. The
steel cables are supported by a tuneframe situated on level 91 that monitors
the building’svibration and regulates the cable movement accordingly.Eight
primary viscous dampers are situated beneath theTMD to absorb and disperse the
vibration impact. Alsopresent is a bumper system of
additional eight viscousdampers to cushion the building vibration, especially
duringtyphoons and earthquakes and then eight primary hydraulic pistons, each
about 2 m long, grip the cradle to dissipate dynamic energy as heat and 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 TMD along with two much smaller
balls installed in the top floors of the building minimizes the sway of the
building to five feet in any direction and that has allowed the Taipei 101 to survive
many powerful winds and over 100 earthquakes.
The TMD is really huge and it also
plays a huge role in stabilizing the building and keeping it from breaking
apart. Aside all that, it also serves a tourist attraction attracting not only
the people in but also the different people all over the world.
