ppt on skyscrapers
DESCRIPTION
Very short and useful ppt presentation on skyscrapersTRANSCRIPT
A skyscraper is a tall, continuously habitable building of over 40 floors, mostly designed for office, commercial and residential uses. A skyscraper can also be called a high-rise, but the term skyscraper is often used for buildings higher than 150 m (492 ft)
Foundations
Skyscrapers are very heavy, therefore we need to have a solid foundation. Why?How do we stop this from happening?
Start on BEDROCK!
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.
Spread Footing
EarthquakesMany skyscrapers are built in cities that have fault lines underneath.There have been many disasters due to earthquakes.
How do we minimize damage?
We use damping systems!
Skyscrapers are built a little more flexible.
Flexibility allows the structure to twist and turn a little without breaking and/or crumbling.
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.
Cross-bracing is sometimes used.
Most of the weight is transferred to the center supports.
Most of the weight is transferred to the outer supports.
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!!
First and Oldest
First skyscraperHome Insurance Building
Location: ChicagoHeight: 138 feet
Stories: 121885-1931
Oldest Still StandingMilwaukee City Hall
Location: MilwaukeeHeight: 353Stories: 151895 - ?