SKYSCRAPERS

Submitted to:Eng.Mohamed rashed

Made by:-1-Mohamed Mostafa Elsayed

2-Mohamed Mostafa Erfaan3-Mohamed Mostafa Kamal

4-Mohamed Yasser Mohamed Shrshar

5-Mohamed Medhat Ahmed Ali

6-Mohamed Yehia Hagar

ContentsIntroduction

1-Raw Materials

2-Design

3-The future

4-Tallest Skyscrabers

5-Funds

6-List of Cities of completed Skyscrabers

7-Advantages

8-Disadvantages

INTRODUCTION:

A skyscraper is a tall, continuously habitable building of many floors, usually designed for office, 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 ahigh-rise anymore. 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.[1]

One common feature of skyscrapers is having a steel framework that supports curtain walls. These curtain walls either bear on the framework below or are possibly suspended from the framework above, rather than load-bearing walls of conventional construction. Some early skyscrapers have a steel frame that enables the construction of load-bearing walls taller than of those made of reinforced concrete. Modern skyscrapers' walls are not load-bearing and most skyscrapers are characterized by large surface areas of windows made possible by the concept of steel frame and curtain walls. However, skyscrapers can have curtain walls that mimic

conventional walls and a small surface area of windows. Modern skyscrapers often have a tubular structure, and are designed to act like a hollow cylinder to resist lateral loads (wind, seismic, etc

The Burj Khalifa, tallest skyscraper in the world since 2010, with a height of 829.8m. Skyscrapers taller than 300m are also called Supertalls, those taller than 600m are called Megatalls.[1]

1-Raw Materials

Reinforced concrete is one important component of skyscrapers. It consists of concrete (a mixture of water, cement powder, and aggregate consisting of gravel or sand) poured around a gridwork of steel rods (called rebar) that will strengthen the dried concrete against bending motion caused by the wind. Concrete is inherently strong under compressive forces; however, the enormous projected weight of the Petronas Towers led designers to specify a new type of concrete that was more than twice as strong as usual. This high-strength material was achieved by adding very fine particles to the usual concrete ingredients; the increased surface area of these tiny particles produced a stronger bond.

The other primary raw material for skyscraper construction is steel, which is an alloy of iron and carbon. Nearby buildings often limit the amount of space available for construction activity and supply storage, so steel beams of specified sizes and shapes are delivered to the site just as they are needed for placement. Before delivery, the beams are coated with a mixture of plaster and vermiculite (mica that has been heat-expanded to form sponge-like particles) to protect them from corrosion and heat. After each beam is welded into place, the fresh joints are sprayed with

the same coating material. An additional layer of insulation, such as fiberglass batting covered with aluminum foil, may then be wrapped around the beams.

To maximize the best qualities of concrete and steel, they are often used together in skyscraper construction. For example, a support column may be formed by pouring concrete around a steel beam.

A variety of materials are used to cover the skyscraper's frame. Known as "cladding," the sheets that form the exterior walls may consist of glass, metals, such as aluminum or stainless steel, or masonry materials, such as granite, marble, or limestone.

2-Design

Design engineers translate the architect's vision of the building into a

detailed plan that will be structurally sound and possible to construct.

Designing a low-rise building involves creating a structure that will

support its own weight (called the dead load) and the weight of the

people and furniture that it will contain (the live load). For a

skyscraper, the sideways force of wind affects the structure more than

the weight of the building and its contents. The designer must ensure

that the building will not be toppled by a strong wind, and also that it

will not sway enough to cause the occupants physical or emotional

discomfort.

Each skyscraper design is unique. Major structural elements that may

be used alone or in combination include a steel skeleton hidden

behind non-load-bearing curtain walls, a reinforced concrete skeleton

that is in-filled with cladding panels to form the exterior walls, a

central concrete core (open column) large enough to contain elevator

shafts and other mechanical components, and an array of support

columns around the perimeter of the building that are connected by

horizontal beams to one another and to the core.

Because each design is innovative, models of proposed super tall

buildings are tested in wind tunnels to determine the effect of high

wind on them, and also the effect on surrounding buildings of wind

patterns caused by the new building. If tests show the building will

sway excessively in strong winds,

An example of a skyscraper ground floor design and 6uilding frame.designers may add mechanical devices that counteract or restrict motion.

In addition to the superstructure, designers must also plan

appropriate mechanical systems such as elevators that move people

quickly and comfortably, air circulation systems, and plumbing.

3-The Future

In 1956, American architect Frank Lloyd Wright announced plans for

a mile-high (1.6-km tall) skyscraper in which 100,000 people could

work. In 1991, another American architect, Dr. Eugene Tsui, designed

a 2-mile (3,220-m) tall building that would provide space for living,

working, and recreation for 1,000,000 people. Although such

buildings may be theoretically constructable, they are currently

impractical. For example, human comfort levels limit elevator speeds

to no more than 3,000 ft/min (915 m/min). To accommodate the

100,000 people working in Wright's proposed structure, the number

of elevator shafts would have taken up too large a portion of the

building's area.

Improvements in elevator technology will be important for future

skyscraper designs. Self-propelled, cableless elevator cars that move

horizontally, as well as vertically, have been proposed, but are still

under development. Computerized car dispatching systems using

fuzzy logic could be refined to carry people more efficiently by

grouping passengers whose destinations are near each other.

4-Tallest Skyscrapers in The World:-

Here a list with The Tallest Skyscrapers in The World.

Ran

kBuilding[A][7] City Country

Heigh

t (m)[2]

Heigh

t (ft)

Floor

s

Buil

t

1 Burj Khalifa Dubai  UAE 828 m 2,717 ft 163 2010

2 Shanghai Tower[8] Shanghai  China 632 m 2,073 ft 121 2014[B]

3Makkah Royal Clock

Tower HotelMecca

 Saudi

Arabia601 m[9] 1,971 ft 120 2012

4One World Trade

Center

New York

City USA 541.3 m 1,776 ft 104 2013

5 Taipei 101 Taipei  Taiwan 509 m[10] 1,670 ft 101 2004

6Shanghai World

Financial CenterShanghai  China 492 m 1,614 ft 101 2008

7International

Commerce Centre

Hong

Kong

 Hong

Kong484 m 1,588 ft 118 2010

8 Petronas Tower 1Kuala

Lumpur

 Malaysi

a452 m 1,483 ft 88 1998

8 Petronas Tower 2Kuala

Lumpur

 Malaysi

a452 m 1,483 ft 88 1998

10 Zifeng Tower Nanjing  China 450 m 1,476 ft 89 2010

Ran

kBuilding[A][7] City Country

Heigh

t (m)[2]

Heigh

t (ft)

Floor

s

Buil

t

11

Willis

Tower (Formerly Sea

rs Tower)

Chicago  USA 442 m 1,450 ft 108 1973

12 Kingkey 100 Shenzhen  China 442 m 1,449 ft 100 2011

13

Guangzhou

International Finance

Center

Guangzho

u China 440 m 1,440 ft 103 2010

14Trump International

Hotel and Tower[11]Chicago  USA 423 m 1,389 ft 98 2009

15 Jin Mao Tower Shanghai  China 421 m 1,380 ft 88 1999

16 Princess Tower Dubai  UAE 414 m1,358 f

t[12]101 2012

17Al Hamra Firdous

Tower

Kuwait

City Kuwait 413 m 1,354 ft 77 2011

182 International

Finance Centre

Hong

Kong

 Hong

Kong412 m 1,352 ft 88 2003

19 23 Marina Dubai  UAE 395 m 1,296 ft 89 2012

Ran

kBuilding[A][7] City Country

Heigh

t (m)[2]

Heigh

t (ft)

Floor

s

Buil

t

20 CITIC PlazaGuangzho

u China 391 m 1,283 ft 80 1997

21 Shun Hing Square Shenzhen  China 384 m 1,260 ft 69 1996

22Central Market

ProjectAbu Dhabi  UAE 381 m 1,251 ft 88 2012

23Empire State

Building

New York

City USA 381 m 1,250 ft 102 1931

24 Elite Residence Dubai  UAE 380.5 m 1,247 ft 87 2012

25 Tuntex Sky Tower Kaohsiung  Taiwan 378 m 1,240 ft 85 1997

26 Central PlazaHong

Kong

 Hong

Kong374 m 1,227 ft 78 1992

27 Bank of China TowerHong

Kong

 Hong

Kong367 m 1,205 ft 70 1990

28Bank of America

Tower

New York

City USA 366 m 1,200 ft 54 2009

29 Almas Tower Dubai  UAE 363 m 1,191 ft 68 2009

5-Fundsmost smallI think the average skyscraper is around $800 million. I mean, most small commercial buildings are about about $10 million, unless in the Bay Area, where that would buy you a fancy box. A good rule of thumb in skyscraper construction is about $7-15 million per story, although even this varies widely due to variations in local costs, taxes, and construction rates. Skyscrapers have become more and more expensive to build.

Here a list with the costs of some skyscrapers around the world.

Ran

kBuilding City Country Height Floors Built

Price

(billion

US$)

1 The Shard London  UK310 metres

(1,020 ft)72 2012 3.9

2 Taipei 101 Taipei  Taiwan509 metres

(1,670 ft)101 2004 1.76

3Petronas

Twin Towers

Kuala

Lumpur Malaysia

452 metres

(1,483 ft)88 1999 1.6

4 Burj Khalifa Dubai United

Arab Emirates

828 metres

(2,717 ft)163 2010 1.5

5

Bank of

America

Tower

New

York

City

 United

States of

America

366 metres

(1,201 ft)58 2009 1

6Chifley

TowerSydney  Australia

241 metres

(791 ft)50 1992 1

6-List of cities by number of completed skyscrapers:-

This is a list of cities by number of completed skyscrapers, a completed skyscraper is a

building that is neither under construction or topped out; it is fully complete, externally and

internally. The majority of international organisations, such as the CTBUH define a

skyscraper as a building that reaches or exceeds the height of 150 metres.[1]

Rank City CountryBuilding

s

1

Hong Kong  Hong Kong 295[2]

2

New York City  United States 231[3]

Rank City CountryBuilding

s

3

Dubai  United Arab Emirates 140[4]

4

Shanghai  China 116[5]

5

Chicago  United States 113[6]

6 Tokyo  Japan 111[7]

7

Guangzhou  China 79[8]

Rank City CountryBuilding

s

8

Singapore  Singapore 70[9]

9 Shenzhen  China 65[10]

10

Seoul  South Korea 62[11]

11 Chongqing  China 51[12]

Jakarta  Indonesia 51[13]

12 Bangkok  Thailand 47[14]

13 Kuala Lumpur  Malaysia 45[15]

Rank City CountryBuilding

s

14 Mumbai  India 44[16]

15

Busan  South Korea 43[17]

16 Nanjing  China 42[18]

17 Panama City  Panama 41[19]

18 Busan  South Korea 39[20]

19 Istanbul  Turkey 38[21]

20 Houston  United States 32[22]

21 Miami  United States 30[23]

Makati  Philippines 30[24]

Rank City CountryBuilding

s

Osaka  Japan 30[25]

Toronto  Canada 30[26]

25

Sydney  Australia 28[27]

Makati  Philippines 28[28]

Shenyang  China 28[29]

7-Advantages:- Throughout the world, the population of the major cities are increasing at a fast rate and where land for building is not available, there is a pressure to build upward rather than sideways. The main advantage of building higher buildings is that they can take the pressure of the need to build just outside large cities, thus preventing the spread outwards and the destruction of the countryside. In smaller countries, land is very expensive and so it makes sense to build upwards. In London, for example, property prices are rising rapidly and will continue to do so for years to come unless more homes are built. Both options, building in the greenbelt around the city and constructing skyscrapers are controversial, but tall buildings are the less damaging alternative. Another benefit is more accommodation and workspace inside the cities, as it shortens the distance that people have to travel to work. Stress is reduced by this and people feel healthier. Moreover, as it is possible to provide more accommodation in a smaller ground space by building upwards, the cost of living is cheaper. -In theory, work may be more productive in skyscrapers. By clustering workers together, it’s easier to meet face to face. Skyscrapers also have their own restaurants, gyms and cafes – all of which help people meet and exchange ideas, both within teams and between firms. Not surprisingly, the typical tenants in tall buildings are business service firms, for whom face to face contact and local knowledge spillovers are very important

8-Disadvantages:- Today, lots of skyscrapers have been built in our world. People should know the skyscraper has many disadvantages to us. The first, because of many people live in a skyscraper, they work and live there. And the environment become noisy, and people can't concentrated on their work and rest well. The same reason, because of lots of people live there, people should wait for elevator long time and don't have enough public space for playing or resting. They don't have enough space to park their cars and the traffic is bad .The second, the skyscrapers have high level, like 30-40 levels or more. if the skyscraper has accident such as fire. people difficult to escape. The third, there are still many people live in low level building, if those low level building next to a skyscraper. Those low level building cant get enough sunshine. its very bad to people's healthy. The last reason is economy, the skyscrapers cant be cleaned or repaired by normal people. they have to cost lots of money to call some professionals to clean and repair the building. Summary, the skyscrapers still have lots of disadvantages to our life. we cant just pay attention on saving land, more place to live and any others. we have to pay attention on those disadvantage and make those disadvantage disappear.