Pile foundations have been around for quite a long time, and to many people justification seems superfluous.
Nevertheless, given the speed of technology advance and the technical amnesia this can create, it is worthwhile to stop and remind ourselves that pile foundations have both economic value and technical appeal.
The whole process is an enormously complex one in all of its aspects, whether we consider the mechanics of the impact or the transfer of the load from the pile into the soil and the soil’s response to it.
In Russia, a country that is admittedly ready made for deep foundations, pile foundations are the most widespread foundations for buildings and structures in civil, military, industrial and hydrotechnical construction because their use instead of ring foundations makes it possible to significantly reduce amounts of earth moving works, to reduce labour consumption by 50%, and concrete consumption by 33-50%.
Pile foundations additionally provide building settlement that is both lower and more uniform than ring foundations.
This fact is especially important in the construction of block-type and large panel buildings, such as the high rise apartment buildings one normally associates with Russia.
To drive these piles and thus reap the benefits of these advantages, the most widespread machines for driving piles are diesel hammers.
Their main advantages are 1) independence from external power sources such as steam boilers, air compressors, generators, or hydraulic power packs, 2) high productivity, 3) simplicity and convenience of operation, and 4)relatively low price of manufacturing.
Eighty percent (80%) of all piling works in Russia are carried out by diesel hammers.
Each diesel hammer during a year fulfils piling works which cost forty (40) times as much as the price of the diesel hammer itself.
The principle of operation of all diesel hammers is based on the two stroke internal combustion engine with compression ignition.
The impact force of a diesel hammer is the result of both the direct impact of the ram on the anvil and the pressure of air-fuel combustion.