HISTORY OF ARCHITECTURE - VBIRTH OF SKYSCRAPERS

IN AMERICA

S T A T E I N S T I T U T E O F U R B A N P L A N N I N G A N D A R C H I T E C T U R E .

Submitted by:-Abhiniti Garg (1304001)Kavita (1304015)Navdha Kabra (1304020)Simran Vats (1304036)

INTRODUCTION:A skyscraper is a tall, continuously habitable building of many floors, usually designed for commercial and residential use. There is no official definition or height above which a building may be classified as a skyscraper and at which height it may not be considered a high-rise anymore.

This definition depends of the relative impact of the shape of a building to a city's overall skyline. Depending of the height of the rest of the buildings and structures in a city, even a building of 80 meters height may be considered a skyscraper provided that it clearly stands out above its surrounding built environment and significantly changes the overall skyline of that particular city.

PETRONAS TOWER

For buildings above a height of 300 m (984 ft), the term Supertall can be used, skyscrapers reaching beyond 600 m (1,969 ft) are classified as Megatall.

OBSTACLES AND INVENTIONS: Two developments in the 19th century paved the way for a whole new type of building: the skyscraper. The first was the development of a safe elevator. Primitive elevators of various designs had been used for centuries, and starting in the mid 19th century, steam-operated elevators were used to move materials in factories, mines, and warehouses. But these elevators were not considered safe for people; if the cable broke, they would plummet to the bottom of the elevator shaft. Then in 1853, an American inventor named Elisha Graves Otis developed a safety device that kept elevators from falling if a cable should break. This new development had an enormous impact on public confidence. And later in the century, the switch to an electric motor made the elevator a practical solution to the problem of getting up and down tall buildings.

OBSTACLES AND INVENTIONS:

The second development took place in Chicago. In 1871, Chicago suffered a devastating fire. In the years that followed, however, instead of recovering slowly, the city experienced explosive growth, and it quickly began to strain against its natural boundaries. By the 1880s, the available land for new buildings in this area could not keep up with demand; the only alternative was to build up. But in order to achieve the desired height, construction techniques had to change. A new method Of building was developed that used a grid of steel beams and columns that were strong enough to support any stresses or forces a building might experience, including both the weight of the floor and the building contents, as well as the force of wind or even, in some areas, earthquakes. And with this new building method, the skyscraper was born and the race for the tallest building began.

USE OF MODERN MATERIALS:Since the birth of the skyscraper, builders and engineers have continuously looked for ways to improve building methods and materials, in order to make structures stronger, taller, and lighter. Skyscrapers are built to last, so they must be made of materials that are strong; durable; resistant to the sun, wind, rain, frost, and snow; and affordable. Concrete is one of the most common materials, beyond the steel supports, because it is enormously versatile. Its composition can be changed depending on the needs of the building. It can be reinforced to make it stiffer and stronger by setting steel mesh or bars into the concrete. And additives can make it set or harden faster or slower depending on the needs of the design.

Another very important material is glass. Because the steel skeleton now supports the main loads of the building, the outer skin only serves to keep the weather out and let light in, the more light the better. So glass walls became very popular beginning after World War II, because they are weatherproof while providing ample natural light, and also because they are so much lighter-and cheaper-than masonry or concrete.

USE OF MODERN MATERIALS:

HISTORY:The tallest building in ancient times was the 146 m (479 ft) Great Pyramid of Giza in Ancient Egypt, built in the 26th century BC. It was not surpassed in height for thousands of years, the 14th century AD Lincoln Cathedral being conjectured by many to have exceeded it. The latter in turn was not surpassed until the 555-foot (169 m) Washington Monument in 1884. However, being uninhabited, none of these structures actually comply with the modern definition of a skyscraper.

The first skyscraper was the ten storey home insurance building in chicago Buit in 1884-1885.In this building, a steel frame supported the entire weight of the walls, instead of load- bearing Walls carrying the weight of the building Which was the Usual method.

HISTORY:Earlier, the walls of a building supported the structure; the taller the structure, the thicker the walls had to be. A 16-story building constructed in Chicago in 1891 had walls 6 ft (1.8 m) thick at the base. The need for very thick walls was eliminated with the invention of steel-frame construction, in which a rigid steel skeleton supports the building's weight, and the outer walls are merely hung from the frame almost like curtains.

In the early 1960s structural engineer Fazlur Khan realized that the dominating rigid steel frame structure was not the only system apt for tall buildings, marking a new era of skyscraper construction in terms of multiple structural systems. His central innovation in skyscraper design and construction was the concept of the "tube" structural system, including the "framed tube", "trussed tube", and "bundled tube". These systems allow greater economic efficiency, and also allow skyscrapers to take on various shapes, no longer needing to be rectangular and box-shaped.

WORLD TRADE CENTRE, NEW YORK

AREA OF WORLD TRADE CENTRE

The "Twin Towers", the original 1 WTC  (417 m), and 2 WTC were the in the world. The other buildings in the complex included the  3 WTC, 4 WTC, 5 WTC, 6 WTC, and 7 WTC. All of these buildings were built between 1975 and 1985, with a construction cost of $400 million The complex was located in New York City's and contained 13,400,000 square feet (1,240,000 m2) of office space.

WORLD TRADE CENTRE, NEW YORK

The core of the towers housed the elevator and utility shafts, restrooms, three stairwells, and other support spaces. The core of each tower was a rectangular area and contained 47 steel columns running from the bedrock to the top of the tower. The floors used prefabricated floor trusses ,supported their own weight as well as, providing stability to the walls and distributing wind loads among the walls. The floors consisted of 4 inches (10 cm) thick lightweight concrete slabs.

WORLD TRADE CENTRE, NEW YORK

Tallest building in the Western Hemisphere• Striking views of the harbor, New York City and New Jersey• Floor to ceiling glass• Column-free floors• 13 ft, 4 inch slab-to-slab floor height• 54 high-speed destination dispatch elevators• Dramatic 55 ft high ground floor lobby• Convenient access to the WTC concourse and 450,000 SF of restaurants, shops and services• Direct access to the Santiago Calatrava designed World Trade Center Transportation Hub linking to 11 subway lines, PATH and Hudson River ferries

WORLD TRADE CENTRE, NEW YORK

45th FLOOR PLAN. 90th FLOOR PLAN.

PETRONAS TOWER, KAULA LUMPUR

Height

Antenna spire 451.9 m (1,483 ft.)

Roof 378.6 m (1,242 ft.)

Top floor 375 m (1,230 ft.)

Technical details

Floor count 88

Floor area 395,000 m2 (4,252,000 sq. ft.)

Elevator count 78

Architect: Cesar Pelli and Associates.

Date of Completion- 1997

PETRONAS TOWER, KAULA LUMPUR