Vertical Cities – Time to build mega metropolis?

While Mumbai and India are still welcoming the skyscraper culture, the developed world has gone a step ahead and is planning to build vertical cities. A vertical city is a city within a city, with complete residential, commercial units as well as gardens and small trams, all within the structure itself!

Currently, skylines are dominated by concrete, glass and steel and are mostly commercial or residential. But a vertical city provides millions of inhabitants all the urban facilities under one roof. Young architects, city-planners and designers are looking for new ways to build science fiction into a revolutionary vision of the future.

But do we really need Vertical Cities? By calculating the rate of growth of population of the world (growing at the rate of 1.4 percent (or 91 million people) per year), the future will not have sufficient amount of land to cater to the growing needs of the people. The only solution then is to build a settlement deep inside the oceans or vertically above the land. Using land for urban habitat is definitely a more sustainable idea. Also on an average a person spends 2-4 hours traveling to and fro per day, that’s about wasting more than 6 years per person in only commuting. Instead this time can be used more creatively. Hence, constructing Vertical-Cities might be a solution.

Architects from various parts of the world believe that in order to make a city life more livable in the future, we should combine – home, office, retail and recreational spaces into one gigantic superstructure. So buildings in vertical scenario will simultaneously act as a residential sector providing all the amenities, such as public space. They will act as an interactive transmitter and receiver for communication, information and media exchange. This will help in reducing the concrete jungle spread over larger piece of land.

So can we physically build perpendicular urban environments? Would they be safe or result in a death trap in the sky? Some structural engineers define a high-rise as any vertical construction for which wind is a more significant load factor than weight. While designing a tall building like a tower or a sky-scraper, various questions arise like, how would you build it? What are the obstacles you would face? What materials would you use? And where would you place it?

Tall buildings require a large base to support their load and keep them stable. In general, the height of a building should be six times its base, so, for a skyscraper 900-m tall, you’d need a base of 150 square m. Tall buildings must stand on firm ground, hence soil analysis is especially critical in facing the threat of natural disasters like earthquakes.

The next obstacle in erecting a super skyscraper is wind. Tall buildings actually sway in the breeze, in much the same way that a diving board bends under the weight of a diver. The real challenge is keeping the structure so stiff that it doesn’t swing too far, cracking partitions, shattering windows and making the upper occupants seasick. As a rule, the top of skyscraper should never drift more than 1/400th of its height at a wind velocity of 150 km/h.

If in a skyscraper, a person hears the wind moaning and whistling by the elevator – that’s stack effect. In any tall building, the difference in temperature and air pressure between the outside and inside the structure pushes air up the stairwells and elevators, like smoke up a chimney. Strong, cold drafts blowing up the building create heating problems and make it difficult to open doors into stairwells. To control stack effect, buildings must be as airtight as possible, with ventilation ducts extending only part way up the building, and revolving doors at ground level. The one invention that, above all, has enabled buildings to climb higher is the elevator.

Bionic Tower, Shanghai
Based on science that mixes architecture with engineering and biology, The Bionic Tower is proposed in Honk Kong Bay, China. Though the first studies were undertaken in 1997 for the realization of the project in Hong Kong, but for different reasons, a new site had to be found and the new plan has been designed.

Statistics:
Height: 1,228m
Inhabitants: 1 lakh
Storey: 300
Area: 2 million sq m
Vertical Communication: 368 Elevators
Tower Dimension: 133m x 100m
Base Dimension: 1 km Dia.
Structure: Micro-structured high strength concrete

The tower is set in the middle of an artificial lake (a large water garden complex) measuring 1000m in diameter, designed to buffer shock waves in case of an earthquake. According to the initial estimates, the complex will take 15yrs to be built. The designs of the tower would also allow lower levels of the vertical neighbourhoods to be completed and inhabited while construction could continue on the successive levels. The tower is composed of 12 vertical neighbourhoods, each with an average height of 80 metres and a variable horizontal elliptical size of 266m by 166m.
The vertical garden city is organised into ‘neighbourhoods’, which are independent from each other. Within these neighbourhoods, there will be urban and green areas similar to those a citizen might enjoy in a traditional horizontal city. The ‘Island Base’ of the tower contains hotels, offices, residential buildings, businesses, sports and cultural facilities, leisure centres as well as extensive gardens, lakes and communication systems. There will be mono-rails serving the Island Base as the secondary means of transport.

Sky City 1000, Tokyo
In 1989, designer/architect Takenaka announced to the world the SKY CITY 1000 concept which advocates multilevel use of urban spaces. Takenaka had planned SKY CITY 1000, a super high-rise, huge multilevel city with a height of 1,000 meters. Compared to other structures like Eiffel Tower, the Sky-City seems to be too large to be believed, but for overgrown cities such as Tokyo, sky-city might be a solution.

Statistics:
Height: 1000m
Inhabitants: 1,35,000
Base Dia: 400m
Top Floor Dia: 160m
Floor Area: 800 Ha (8 sq kms)
Floors: 14 concave dish shaped plateaus having 10 floors each
Height of each Plateau: 56m
Height of each Floor: 4m

Sky City will be one quarter of the total height of Mount Fuji (3,800m approx.), have an interior space 120 times more than the great pyramid of Egypt (6.6ha.) and contain an area of 120 Tokyo city blocks. It will have new transportation system to carry residents and visitors along the 10 storey high rises that ring each plateau. Inside each plateau, there will be apartments, hotels, shops, restaurants, offices, entertainment and sports complexes and all the services of urban life.
The high rise phenomenon is catching up fast in our country. To share more information and knowledge and facilitate business exchange the Council on Tall Buildings and Urban Habitat (CTBUH) is coming to Mumbai and organizing a conference from the 3rd-5th February 2010 at Hotel Renaissance and Convention Centre, Powai.

The Council on Tall Buildings and Urban Habitat (CTBUH), based at the Illinois Institute of Technology in Chicago, is one of the world’s largest international not-for-profit organization with a organizational network including 387,584 individuals working in 3,209 offices around the world: architects, engineers, developers, building owners, financiers, contractors, consultants, urban planners etc. Founded in 1969, the Council’s mission is to disseminate multi-disciplinary information on tall buildings and sustainable urban environments, to maximize the international interaction of professionals involved in creating the built environment, and to make the latest knowledge available to professionals in a useful form. For more information on the council log on to www.ctbuh.org.

The World Conference will see over 700 delegates and more than 50 global speakers gather to disseminate their best knowledge, network and put together a world class conference that will build a roadmap towards the colossal growth of the Industry. Its theme for the three day event is Remaking Sustainable Cities in the Vertical Age. For more information, registration and details can be accessed at www.ctbuh2010-india.com