Applying this method, a pipe with a closed, non-fixed end is vibrate into the ground. A spatial fitting framework is mounted into the pipe, concrete is laid and the pipe is extracted while vibrating it. This mounting method of piling foundations is quite quick and economic. The thrusting piles are mounted without removing ground, which gives quite a large holding power for the mounted piles. This method is used for mounting of foundations of multi-storey buildings and production workshops. But the foundations of thrusting piles fit for the construction of private houses, especially under the unfavourable geological conditions: there is an artificially piled layer of ground or peat, high ground water level or other factors restricting the use of other technologies on site.
Applying this technology, the ground from the future pile place is drilled out, and the emerged hole is filled in by concrete and spatial fitting framework. The most reliable and qualitative method of mounting the screwed piles is CFA – Continuous Flight Auger technology, when the ground is drilled by a hollow screw, and a concrete mixture is pumped up through a driller, take out in the middle, filling up the emerged hole. After the boring place is concreted, a spatial fitting framework is mounted.
This pile installation methods comparable with CFA installation method is characterized in that the hollow drill bit used for drilling the rotational casing tubular. Mounting the screwed piles in this way, the drill rotates clockwise, while the protective pipe – remains before it. A drill and a pipe rotate in the opposite directions, so the ground is less loosened and obstacles – stones or old foundation are drilled out. This mounting method is used to working in a densely built-up areas (eg. in older cities and so on.) When you need to drill a pile close to the existing building foundations, as well as to mount new deep foundation pits (eg. cellars, underground parking, etc.). Working in densely built-up areas near buildings, a traditional drilling method or a continuous flight auger method (CFA) applications are very limited, because drilling in all cases can destroy the ground under the adjacent building foundations. VDW drilling method can not only equipped with individual piles, but piles and intersecting walls, which are recommended for mounting underground structures, where there is a high water level.
It is expedient to mount this type of a pile in watery grounds or near the present buildings, where vibration or extract of ground is not allowed while drilling, because it may bring up subsidence risk for the nearby buildings.
Applying this method special equipment is used when a special pipe with coils is screwed up. Screwing up the pipe, ground is not removed from the boring place, but pushed aside, so the holding power of the FDP base is equal to the holding power of the trusting pile base. During the extraction of the pipe, concrete is fed thought the cavity and the boring place is filled in by concrete. After extracting the pipe, the armature framework is sunk into the boring place.
Another methods of screwed piles is also used. Screwing of the SVB piles are held as a mounting method with partial ground removal. A special pipe with a thread is screwed into the ground, which serves simultaneously as a protective pipe. The pipe bottom is closed with a bending drilling tip. Screwing this pipe, a very small part of the ground is raised from the boring place with the thread blade under the pipe, but the majority part of the ground is pushed horizontally and it is not removed from the boring place. After the pipe is screwed into the right place, the fitting framework is mounted and the pile is concreted. The protective pile is screwed out.
Ground anchors are structural elements used for supportive walls, assuring the stability of operating ground pressure. A ground anchor is mounted by drilling a hollow bar with a fitted drilling head of a proper diameter. Cement solution is injected under a high pressure through the holes of the drilling head, while drilling. As soon as the design strength is reached, the anchors are tested, then a supportive structure is mounted.
Micro-piling is used for metallic, reinforced-concrete structures, supportive walls, foundation reinforcement, as well as assuring stability of structures. Micro-piling is mounted by a special device drilling a hole in the ground and placing an anchor, the cavity is then filled in by cement solution through the cavities around.
Under the favourable geological conditions and low loads upon the building foundations, the shallow foundations may be mounted. A classical method is mounting of assembled foundations from the plant prefabricated reinforced concrete blocks. Foundational blocks are mounted on the consolidated gravel layer. Monolithic foundation structure may be mounted instead of prefabricated blocks when lining are built, fittings are mounted and concreting is done with the certified concrete mixture.