TALL BUILDINGS

What is a tall building? Why do people build tall building? Where to construct a tall building? How to measure a tall building?

How to build a tall building?

Stonehenge 2500 BC ? 76 feet (23m) tall

Egyptian Pyramids 2500BC 480 feet (146m) tall

Tower of Pisa 1350 AD 183 feet (56m) tall

Empire State Building 1931 102 stories 1453 feet (443m) tall

Burj Dubai 2008 162 stories (850 m)

INTRODUCTIONTallness is a relative term A tall building is not defined by the height or number of stories Primarily affected by lateral forces from wind and earthquakes Aspect ratio (height/structural lateral system footprint width or depth) Preferably 10 if special features to improve wind comfort are included

A building whose height creates different conditions in the design, construction, and use than those that exist in common buildings of a certain region and period.The Council of Tall Buildings and Urban Habitat

A building whose height is 35 meters or greater, which is divided at regular intervals into occupiable levelsEmporis Data Community

Based on Number of Stories:1-10 Low rise 10-40 Mid rise >40 High rise

Based on the structural or service system

Humans have always admired tall structures since ancient times because of their social status: they are visible to all. Their builders were held in the highest respect of their societies, and their structures are the subjects of legends

Modern tall buildings were born in 1885 with the first all metal structure of the Home Insurance Building in Chicago. The demand for tall buildings has almost exclusively been for commercial and residential use. Tall commercial buildings have served as prestige symbols for corporations In Hong Kong and Rio de Janeiro housing is usually 40-story towers spaced only a few meters of each other. The increasing growth of the tourist industry demands taller hotels in city centers where land is scarce and expensive.

Scarcity of land in urban areas Increasing demand for business and residential space Economic growth Technological advancements Innovations in Structural Systems Desire for aesthetics in urban settings Concept of city skyline Cultural significance and prestige Human aspiration to build higher

Evolution of Building Design Approach Short Building : Strength Design Gravity Control (~h) Strength Design ( ~h 2 ) Intermediate Size Building: Deflection Lateral Load Control Stiffness Design ( ~h 3 ) Tall Building: Wind Induced Bldg Motion (acceleration) Control Dynamic Stiffness Design ( ~h 3 )