Design and Construction of Tall Buildings.

The world is building at an ever- increasing pace to house the rapidly growing population, to replace deteriorating or obsolete buildings, and to satisfy the demand for accommodation of higher quality. More and more buildings of all types are needed, from jungle huts to the tall giants of the modem metropolis.

The need for tall buildings is increasing rapidly. Urban renewal schemes for decayed areas within the central cores of many large cities are feasible only by replacing the existing buildings of moderate height by fewer but significantly higher buildings, which, while increasing the population density, provide more open space and green areas.

A great deal of thought, research and experimentation has gone into the existing tall buildings. The aspects are manifold and involve a number of disciplines of learning: sociology, economics, architecture, and many branches of engineering. The scarcity of land in the desirable central parts of cities is undoubtedly one of the basic reasons for tall buildings. High land values make the erection of tall buildings the only economical way to build. Economic considerations were the prime movers in the erection of the early skyscrapers in the latter part of the last century.

The prestige value of tall buildings is undoubtedly another reason that has prompted buildings owners to strive for greater heights.

The desire to preserve the central core of city, and to limit the urban sprawl, are further factors which favor tall buildings. The increased permitted population densities combined with requirements for ample pen space, make tall buildings the only practical way for the effective urban renewal schemes.

Another reason for large, tall buildings is the demand of large organizations for bulk office space in one building in central city areas.

It is rather difficult to define a tall building. "Tall", being a relative term, changes its absolute meaning with time and locality. For instance the first Chicago "skyscraper", built in 1885, had only 10 f1oors. Generally, a "tall building" must extend above what is considered average or commonplace in any particular location, at any given time.

The history of the early American tall buildings, or skyscraper, as they are generally called, is closely associated with the cities of New York and Chicago.

Until the middle of the 19^th century the height of commercial buildings was generally limited to 6 f1oors, because the tenants and their clients were reluctant to climb higher. The invention of a safety device by Elisha G. Otis in 1853 made the use of the elevator acceptable for passenger transport, and cleared away one of the major obstacles for taller buildings.

In 1870, a 130-ft-high building (40 m) fully equipped with elevators was completed in New York, and in 1875 the tallest building in the same city reached the height of 260ft (79 m). The first building with a complete iron frame, where masonry was used only as a space-enclosing element, was built in Chicago in 1885: the 10-stries Home Life Insurance Building.

The construction of tall buildings spread rapidly during the following years. At the turn of the century 74 "tall" office buildings, the tallest around 20 stories, were standing in New York. In Chicago the tallest building reached the height of 21 stories (305 ft). Other American cities followed suit.

After the end of World War 2 the construction of tall buildings gathered new impetus and spread to many countries. There are now many outstanding examples of tall buildings throughout the world.

The principle use of tall buildings is for offices, but their use for residential purpose has been growing steadily, particularly in the last 10 to 15 years. And, of course, there are many notable applications in the field of hotel and institutional construction.

Earlier office buildings depended mainly on natural lighting and ventilation.

Since World War 2 there has been a notable swing to artificial lighting and air-conditioning and now these features are incorporated in all new tall office buildings in North America. Residential buildings, however, still rely to a large extent on natural light and ventilation.

From the town planning point of view, the nearly unlimited freedom of the early skyscrapers builders has been severely curtailed by the enactment of building bylaws, which do not permit the creation of dark canyon- like streets. The contemporary tall buildings are erected on relatively large building lots, above a certain height.

Some of the features which distinguish the contemporary tall building from its earlier relatives are: the exterior walls are now largely of lightweight materials; glass, aluminum and precast concrete have replaced the masonry; the service - air-conditioning, lighting, vertical transportation, communication - have grown and are more complicated; the interior and exterior details are planned with ease of maintenance in mind; the internal walls are light, and easily adjustable to the varying needs of office layout; the appearance is simple and free of ornate detail.

EXERCISES

1. Read and translate the text.

2. Make a detailed plan of the text.

3. State the main idea of the text and make the annotation.

 

 

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