Современные проблемы промышленного и гражданского строительства на занятиях английского языка. Кузьмина Е.В. - 59 стр.

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building is important if the structure is to withstand storms. The snow load may

also be an important factor. In some areas, buildings have to be constructed to

withstand earthquake shocks.

Foundations are the chief means of supporting a building. They carry

both the dead and live loads. There are three main types of foundations: spread,

pier, and pile.

Spread foundations are long slabs of reinforced concrete that extend

beyond the outer edges of the building. Such foundations are not as firm as

those based on solid rock. The footing areas in contact with the soil must be of

sufficient size to spread the load safely over the soil and to avoid excessive or

uneven settlement. Any such settlement would cause walls to crack or doors to

bind.

Pier foundations are heavy columns of concrete that go down through

the loose topsoil to a bed of firm rock. This bed may also be sand, gravel, or

firm clay. If the bed consists of firm clay, the pier is usually enlarged at the

base, to increase the bearing area.

Pile foundations are long, slender columns of steel, concrete, or wood.

Machines, called pile drivers hammer them down as deep as 60 meters to a

layer of solid soil or rock. Workers can tell when the columns reach their proper

depth by the number of blows the pile driver needs to drive the columns a few

centimeters deeper. These columns transmit the building load to the supporting

soil. Most skyscrapers are supported by rock foundations.

Types of construction

In load-bearing-wall construction. The walls transmit the load to the

foundation. In skeleton construction, all loads are transmitted to the

foundation by a rigidly constructed framework made up of beans, girders and

columns. This skeleton carries the roof, walls, and floors, together with their

loads. Load-bearing-wall construction is usually most economical for buildings

less than four storeys high, but skeleton construction is better for taller

buildings. All buildings in the skyscraper class are of skeleton construction.