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40
UNIT 7
TEXT A. PILE FOUNDATIONS
The durability of a structure depends on how the foundation is built and
on the property of the ground.
Prior to the beginning of the last century buildings were put up mostly on
stable ground. Bands of stone and baked bricks bound together by lime mortar
served as foundations.
Our ancestors could not even imagine on what kind of ground we would
build. Towns and cities have appeared in places where there had recently been
swamps, on the permafrost ground of the northern regions of the country. Pile
foundations are widely used there. They cut through the unstable thickness of
the ground and rest upon firm layers.
Piles were also used in ancient times. Peter I widely used piles in building
the city. Interestingly, Ivan the Great’s bell tower in the Kremlin (about 500
years old) also stands on a peculiar pile foundation. The base is comprised of
round, closely bound upright logs from 120 to 180 cm high. In those days there
were no mechanisms to drive in piles – that accounts for their being so short.
Upon the piles rests a massive stone slab. The piles are submerged in water to
protect the wood from destruction.
Ferro-concrete was discovered about 200 years ago. Wooden piles
gradually became a thing of the past. The have been replaced by ferro-concrete
and metal piles.
During the last few decades pile boring has found wide application. A
bore hole is first filled with steel framework, then with concrete, and the pile is
ready
A group of specialists has developed piles without using building
materials for the purpose. At the depth of 16-18 m a hole is drilled. A special
burner is then inserted. At 1,400
o
C the earth fuses. It then hardens and
becomes a bearing pillar. Several buildings have already been erected on such
“piles”.
The foundation of the Alma-Ata TV tower is quite original. The tower
was built on a small site in the mountains, where force 10 earthquakes can
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