In the world in almost any country can be foundhouse on stilts. In some parts of the centuries, housing has been built on wooden logs dug vertically into the ground. This technology allows to build housing even on the water. In recent decades, no one is surprised at a house on stilts made of concrete. In modern construction came a real revolution after the use of screw piles for the construction of light buildings.
A house on stilts is an ideal solution to the problem of construction where the ground does not fit a monolithic strip foundation. It can be built on plots with the following features:
• with the previously created landscape;
• with a difficult relief;
• with high soil moisture;
• where it is impossible to carry out earthworks;
• in areas with a deep level of soil freezing.
Building houses on stilts is very populartoday, but especially in demand are metal supports that make it possible to build quickly small buildings with your own hands. The advantages of such buildings are:
• saving time and cost of construction;
• the ability to work on problem soils;
• no need for soil leveling;
• the possibility of building wooden structures on lawns, slopes, near trees;
• high piles protect the house from the penetration of rodents;
• during the flood, the dwelling is protected from possible flooding;
• the use of high piles makes it possible to use the site located under the house for parking the car, the summer kitchen or the sports ground.
Despite recent advances inconstruction, some old ways of erection of buildings are successfully used to this day. A house on wooden piles is a typical construction method, popular in many states. So in Russia for many centuries wooden houses were built on logs of wood. They are often called "chairs." For such piles are used trunks of those tree species, which are characterized by a long service life. These include pine, oak, larch. The minimum diameter of such "chairs" to create a solid foundation is 20 cm. The more it is, the better. To extend the life of wooden piles they are subjected to fire treatment - burned. In the ground, scorched wood does not rot very well, which makes it possible to erect buildings whose service life is many decades (at least 30 years). Today, the treatment of piles with fire is often replaced by impregnation with special antiseptics or with bitumen coating.
Since today there is enough for salethe number of available high-tech piles made of metal, the construction of houses using logs goes to the background. Most often they are used for summer frame or wooden structures.
Дом на сваях, фото которого находится сверху, would require digging quite deep holes under the logs. The minimum depth for inserting wooden piles is 1.25 m. They should rest against bars with a section of 10x20 cm and a length of 40-50 cm. Wooden piles are in all corners of the building and are located along its perimeter (with a distance of 1-2 m). Backfilling pits produce layers of 20 cm. Each of them carefully rammed. The upper 30-40 cm backfill produced using fine granite rubble or gravel.
• the difficulty of digging in logs;
• the need for additional wood processing;
• short service life of piles in comparison with other products of this type;
• the sale of more high-tech building materials;
• high price for quality wood.
Foundations built with screw pilesfor a long time used for the construction of military facilities. This specialization is due to the fact that their design allows the construction of reliable supports for a variety of buildings in the shortest possible time. Abroad, modern technology of building construction on pile foundations was mastered decades ago. It is used for the construction of residential buildings, outbuildings, as well as various industrial structures.
В РФ эти основания длительное время used exclusively for the construction of lightweight structures, since the screw piles on sale were characterized by a low load carrying capacity. Recently, modern varieties of metal supports have appeared, which allow us to make the scope of application of such building materials much wider.
Screw piles under the house - the main elementfoundation. They are a steel pipe, the thickness of the metal is not less than 4 mm. On the one hand, it has a sharp point. At this end of the pile is located the cutting blade, with which the support is screwed into the ground. Many people think that the use of such building materials will require the use of special equipment. In fact, the ideal shape of the blades of the screw piles allows them to be screwed to the required depth by 3-4 employees.
For the construction of objects with differences in heightor with different lateral loads, piles with two blades are used. This design gives the foundation additional reliability. The diameter of the blades of the screw piles varies in the range of 200-850 mm. The supports themselves have a diameter of 50-350 mm. The length of screw piles can be 2–11 m. Not only hollow, but also solid piles are available for sale.
• reusability due to easy disassembly without damage;
• no need to perform significant amounts of earthworks;
• the possibility of building houses on mobile and flooded areas;
• speed of construction of the foundation;
• the beginning of the construction of the building immediately after the foundation has been laid
• the possibility of using for the construction of various extensions;
• long service life exceeding 100 years;
• acceptable cost, which is almost three times less than the price of strip footing;
• lack of construction waste on the site;
• the possibility of replacing or repairing the foundation.
Благодаря оптимальному перпендикулярному the location of the blades screw pile when screwed into the ground does not loosen it. The bearing capacity of such materials varies in the range of 5-25 tons. For the construction choose piles with cast tips. The best protective coating of such supports is made on the basis of polyurethane resin. Very reliable galvanized piles, covered with protection from the outside and inside.
The cost of the foundation of the screw supports depends on the size of the house. So, for example, a construction with an area of 6x6 m will cost 1-1.2 thousand dollars, and 9x12 m - 3-3.3 thousand.
• inability to use on rocky or coarse soils;
• деформацию фундамента, возможную в случае violations of technology devices. It occurs when, during the twisting of the piles, their position was not fixed, the piping was performed incorrectly, screws were hammered or placed in the dug holes;
• subsidence of soil, resulting from poor quality inspection of the site;
• corrosion of piles with poor quality of anti-corrosion environment;
• impossibility to build large houses using heavy building materials.
There are several options for projects such foundations. They are selected depending on the type of the future house and the ground on the site. The most common project foundations:
• single piles supporting individual elements of the structure, used when a small extension is made to an existing building;
• standard foundation, which is built under the basic elements of the building;
• pile tape, located under all walls of the house;
• Pile field, required for the construction of the foundation for heavy structures.
The house on screw piles is built in several stages:
one.Creation of the project structure and calculation of the number of screws. Most often under the frame and wooden houses choose piles with a diameter of 108 mm. For smaller buildings, you can choose smaller screws, which will save money. When calculating the required number of piles, it should be remembered that with too often installed supports, the reliability of the foundation practically does not increase, but its cost significantly increases. One pile, after filling it with concrete, can withstand a load of 5-9 tons, so the distance between them during the construction of frame houses can be 3-5 meters. The number of supports is increased during the construction of two-story buildings or the use of heavier building materials. To increase the reliability of the pile-screw foundation, its carrying capacity is increased by 25-30%.
2. The site is marked and pre-prepared.
3The type of foundation is chosen depending on the mass of the structure under construction, the type of soil and the depth of its freezing. Begin construction with a geodetic study of the soil. It is necessary to determine the location of groundwater and stable layers of soil.
four.Piles are screwed into the ground according to the produced marks. At the same time in the area of the screw soil compaction occurs, contributing to the strengthening of the foundation strength. These works can be carried out in any weather. Pile screwed at least 3 employees: one monitors the level of support, and the other two screwed it to the desired mark. Props cut at a single level and fill them with concrete. It gets inside the pile pipe, which strengthens the pile and prevents metal corrosion. After the concrete solidifies, they proceed to welding to the support of the metal head.
five.It is necessary to make a harness of piles for uniform distribution of the bearing load. Most often it is made of channel. The upper part of this foundation is called grillage. It redistributes the load bearing structure.
6Warming of the pile and screw base is not required, as it relates to the ventilated type. Sometimes a grillage is being insulated, but if the work is performed incorrectly, moisture may appear, which affects the entire building. Best for saving heat in the house to make the floor insulation of the house.
7. Frame or wooden houses are erected on the prepared pile foundation.
8. Make the base of the foundation attached.
Weighing the pros and cons of choosing one or anotherof the type of support, it is possible to say with confidence that the modern pile-screw foundation has more advantages than the wooden one. It surpasses the latter not only in technical, but also in economic and labor-intensive indicators. Moreover, its durability is many times longer than the service life of log supports.
