Современные проблемы промышленного и гражданского строительства на занятиях английского языка. Кузьмина Е.В. - 42 стр.

UptoLike

Составители:

Рубрика:

In order to distribute a column load over the foundation bed, steel grillage

is occasionally used instead of a reinforced concrete footing. This usually

consists of two layers of beams. The beams are encased in concrete not less

than 4 in thick as a means of protection, and the lower tier rests upon a bed of

concrete to distribute the column load to the foundation bed. Since the grillage

beams must be completely encased in concrete, the bearing areas of the grillage

foundation and a reinforced concrete footing are practically the same.

Therefore, it is usually expedient to use the reinforced concrete footing. In this

case the concrete resists lending, shearing, and bond stresses instead of merely

being a protecting material for the steel grillage beams.

TEXT D. THE FOUNDATION OF THE OSTANKINO TV TOWER

The reinforced concrete tower of the TV center in Moscow was built

latter the design of Nokolai Nikitin. The tower is 535 m high. The 32-thousand-

ton tower rests upon a monolithic hoped reinforced concrete foundation 9.5 m

wide, 3 m high and 74 m in diameter. In the 10-angled reinforced concrete band

of the foundation prestressing was created by means of a system of stressed

hooping.

The depth of the foundation is 4.65. It is assumed that it will settle from 3

to 3.5 cm. The stability of the tower has a six fold margin of safety.

The 8

International Soil Mechanics and Foundations Congress

recognized N. Nikitin’s idea of building the foundation at the depth of 4.65

m to be a brilliant one.

While the foundation was being built, specialists expressed their concern

that the depth was insufficient for such a high tower. Relying on the experience

of putting up high-rise structures, specialists suggested a hypothesis stressing

the necessity to plant the base of the TV tower on supports resting upon a rock.

Scientists were of the opinion that because of the insignificant depth of

the foundation, ground work in its vicinity (the building of collectors, tunnels,

metro lines etc.) could result in the loss of earth from under the foundation. The