Skyscrapers
Construction Technology
What is the tallest skyscraper?
Burj Khalifa
(Burj Dubai)
Location: Dubai, United Arab Emirates
Stories:160 Inhabitable + 46 Maintenance
Overall Height: 2,717 ft
Highest Point of Occupancy: 2,038 ft
Began: 2004
Completed: January 2010
Elevators: 57
(40 MPH)
Architect: Adrian Smith
Cost: 1.5 Billion
Over 2000ft. high!!
Foundations
Skyscrapers are very heavy, therefore we
How
we stop
from happening?
need do
to have
a solidthis
foundation.
Why?
Start on
BEDROCK!
Framing
Skyscrapers are framed using steel columns and girders.
The outer covering is called a curtain wall.
Spreadthe
Footing
Spreading
weight
Even though the foundation has started on bedrock, we still
need to spread the weight; just to be safe.
How can we do this?
Typically, they use SPREAD FOOTING.
Wind
Most skyscrapers sway in the wind.
How can we minimize the
distance of the sway?
Engineers use TUNED-MASS DAMPERS.
1. A computer detects how far the wind is making the
building move in one direction.
2. The computer will move a very heavy weight in the
opposing direction.
3. Within under a minute, the sway is minimized to a safe
level.
Tuned-Mass Damper
Notice the
size
compared
to the guy!!
Earthquakes
Many skyscrapers
There have been
are built
many
in cities
disasters
that have
due tofault
earthquakes.
lines underneath.
How do we minimize damage?
Skyscrapers are built a little more flexible.
Whatallows
effects
you think
thisand
hasturn
on a
Flexibility
thedo
structure
to twist
thebreaking
overalland/or
design?
little without
crumbling.
We use damping systems!
If the skyscrapers were rigid, pieces would snap off
easily in an earthquake.
ALSO…
Also…
Glass is attached using rubber channels.
This allows the glass to move a little bit. It has
a lower change of breaking in an earthquake.
For Extra Support
Cross-bracing is sometimes used.
What kind of
cross-bracing
should be used for
this skyscraper?
Most of the
weight is
transferred
to the center
supports.
Most of the
weight is
transferred
to the outer
supports.
First and Oldest
First skyscraper
Home Insurance Building
Location: Chicago
Height: 138 feet
Stories: 12
1885-1931
Oldest Still Standing
Milwaukee City Hall
Location: Milwaukee
Height: 353
Stories: 15
1895 - ?