Pile foundations

The durability of a structure (depends/is depended) on how the foundation (builds/ is built) and on the property of the ground.

Prior to the beginning of the last century buildings (put up/were put up) mostly on stable ground. Bands of stone and baked bricks bound to­gether by lime mortar (served/ were served) as foundations.

Our ancestors could not even imagine on what kind of ground we (would build/would be built). Towns and cities (have appeared/have been appeared) in places where there had recently been swamps, on the permafrost ground of the northern regions of the country. Pile foundations (use/are used) widely there.

Piles (used/were used) in ancient times. Peter the Great widely (used/was used) piles in building the city. Interestingly, Ivan the Great's bell tower in the Krem­lin (about 500 years old) also (stands/is stood) on a peculiar pile foundation. The base (comprises/is comprised) of round, closely bound upright logs from 120 to 180 cm high. Upon the piles (rests/is rested) a massive stone slab. The piles (submerge/are submerged) in water to protect the wood from destruc­tion.

During the last few decades pile boring (has found/has been found) wide application. First a bore hole (fills/is filled) with steel framework, then with concrete, and the pile is ready.