- №1.Types of piles for manufacturing material
№2.Types of piles according to
- Wooden piles
- Metal piles
- Reinforced concrete piles
bored piles. Types of piles according to the type of impact on the ground №4.Types of piles in the form of section №5.Calculation of the number of pile supports
- installation technology Drop-in piles
- Screw piles
- Depressed piles
- No. 3
Construction of a cottage, private house or cottage does not do without the construction of the foundation. This is the basis of the basics. The durability of the erected structure depends on the correctly chosen type of foundation and the quality of its execution. In private construction, different types of bases are used, but more and more often the choice falls on the pile foundation. It can be used on any type of soil, regardless of the level of groundwater, allows you to carry out all the work as soon as possible, but for its arrangement requires special equipment. In addition, it is necessary to determine the type of piles, because depending on the material, installation method and other features, their properties are very different. We learn to choose piles for private construction and understand their key features.
№1.Types of piles by material of manufacture
All piles that are used in private construction can be divided into the following types of material by material of manufacture:
- reinforced concrete.
Wooden piles are excellent for private construction. They cost cheaper than metal and reinforced concrete , and cope with small loads just as well. Today, wooden piles are used in the construction of cottages, temporary structures and small bridges.
The raw material for production is larch, cedar, oak, pine or fir wood. Use a healthy straight forest winter felling. Piles can be whole and spliced. Solid ones have a length of 4.5-16 m, spliced - up to 25 m. When splicing occurs, individual segments are joined end-to-end with the help of overlays. However, for private construction the length of solid piles will be enough. The splicing technology is sometimes used to increase the diameter - this is the batch splicing .
The lower end of the wooden pile gets sharpened, its length is about 1.5-2 diameters. If the dive is carried out in solid ground with numerous obstacles, the tip is protected by a shoe. The upper part is also protected by a head cover, because the installation of the pile is carried out by blocking, indentation or exposure to vibration.
Metal piles can withstand more severe loads than wood, but they are also more expensive. On such a foundation, large brick cottages are being built, as well as lighter frame houses and timber houses. Metal piles are suitable for strengthening the emergency foundation, as well as when creating extensions to an existing structure.
These products are made from seamless steel pipes, but steel dowels, I-beams and other rolled sections can be used. The diameter is from 25 cm to 100 cm or more, and the bases of the box section are also produced. As a rule, metal piles get a pointed tip, but it may not be. If the weight of the building is large, then the can be strengthened by filling the hollow metal piles with concrete, but this is rarely used in private construction.
should be singled out separately: screw piles, they have blades at the end, thanks to which they have enhanced strength properties. Screw piles are immersed by screwing. With their help, they make a foundation for extensions, since there is no dynamic load on the ground. Often screw piles are used to reinforce emergency foundations: they are installed along the contour of such a base and attached to it with the help of special brackets. Normal manufacturers cover an product with an anti-corrosion coating, but even under it you can consider the quality of the welds. Welding should be performed with a solid seam, using wire technology. The quality of the anti-corrosion coating can be assessed by trying to scratch it a little with a key or a coin: normally, this will not be so easy.
Screw piles can have a welded or cast tip. Cast, of course, is better, but welded in private construction will also fit - the loads here are small.
Reinforced concrete piles
Reinforced concrete piles in private construction are used less frequently - they are designed for more serious loads and are indispensable in high-rise and industrial construction. Nevertheless, on weak and mobile grounds and in conditions of a sharp change in soil moisture such piles will be the best option for the construction of cottages.
Reinforced concrete piles are available in two variations:
- national teams.
Monolithic piles of have a square or rectangular section, side from 20 to 40 cm. They receive longitudinal reinforcement with prestressed or non-stressed reinforcement, transverse reinforcement is performed using low carbon wire with a cross section of 5 mm. Monolithic piles are also produced with a cavity inside a cylindrical shape, but the wall thickness in them should not be less than 4 mm. When immersed in the ground, monolithic piles are protected by a steel shoe. The upper part, which takes on the shock load, is covered with a cap in the form of several grids.
prefabricated piles are assembled from several sections, the length can be anything. As a rule, assembly is carried out in advance, but especially long piles can be assembled at the installation site.
Reinforced concrete piles are mounted using the blocking method, which is their main lack of .Not only is it noisy, so also in areas with dense buildings changes in ground mass can occur. Another disadvantage is difficulties in terms of transportation, because RC piles are large, heavy and fairly easily damaged. They must be transported in horizontal rows with the same orientation of the ends. Between the rows it is better to lay wooden linings, and round piles are transported together with special bars, which will not allow them to slide.
Nevertheless, the has the advantages of for RC piles of piles. With their help, you can create a solid and reliable foundation. Moreover, when they are driven down, the soil is compacted in the diving area, which has a positive effect on strength.
is also made from reinforcement and concrete; they are only created directly at the construction site by pouring concrete into the drilled wells.
№2.Types of piles using
installation technology Drop-in piles
These are, as a rule, reinforced concrete piles with a pointed end. Installation occurs through the use of special drums. Piles are protected from destructive loads due to the headgear.
The main advantages of the of such piles include versatility: the method can be used on any soil and in any weather. The speed and productivity is high, and the soil around the pile is slightly compacted, which increases the bearing capacity of the future foundation. Among cons - the inability to use near other buildings, since the consequences of the impact of a shock wave can be devastating.
Vibro immersion piles
Making a pile sink into the ground can be, if you influence it by vibration. Vibration is transmitted to the ground, reducing its force of friction and resistance. The soil becomes floating, and the pile plunges under the influence of a body weight. With such an impact, the soil around the pile is also compacted, so we can talk about the natural strengthening of the foundation. This method is used when dealing with sandy and water-saturated soils. It is more difficult when working with low-moisture and dense soils, and for rocks, the vibration method is not suitable at all.
Among the advantages of vibratory submersible piles is less noise and relatively low construction costs. Of course, one cannot do without special equipment, but it can be rented. Residents of Moscow and the region may contact IntelStroy, which rents vibratory pile drivers, and with qualified personnel. All details can be found on the page http: //vibrorent.ru/ arenda-catalog /.
Screw Piles. The screwing method is used for metal and reinforced concrete piles with a steel tip. Screw piles are distinguished by the presence of blades at one end, due to which they enter the ground. Installation can be done manually, but it is easier to use special equipment.
Screw piles are used on loose and flooded soils, as well as when it is necessary to build a foundation in a densely built area, so that when building a house in the city is a great option.
In private construction, such piles are used extremely rarely. The pile is affected by a large static load, and the equipment that creates it requires a sufficient amount of free space. This method is used when working with solid and dense soils.
This is a separate type of pile. These are created directly on the site of the foundation construction. The creation process consists of the following stages:
- preparation of wells using a percussion or rotational drill;
- casing installation or concrete pouring, depending on which method is used. If the option with casing pipes is chosen, then first a special pipe is immersed in the well, which will strengthen the walls. Otherwise, during the drilling of the well, a solution of concrete is poured, which has the same function - to strengthen the walls;
- immersion in the well;
- pouring concrete. In some cases, casing pipes are then pulled out, but often pipes that cannot be dismantled are used.
The advantage of the method is relative simplicity and low cost, therefore this method is very popular in private construction. It will not be necessary to transport long piles, but it will be necessary to prepare a large quality of concrete, and there is nowhere without a concrete mixer. Experts say that the unpleasant feature of this method is the inability to control the quality of the produced piles. As for the restrictions, then on soils prone to swelling and horizontal movement, such a foundation can not be used.
№3.Types of piles according to the type of impact on the ground
According to the type of impact on the ground or according to the nature of the work, the piles are divided into two types: support
- , or piles. When immersed in the ground based on a stable soil. Suitable for those areas where under unstable soil at a shallow depth there is a dense stable soil;
- suspension piles .They transfer the load on the soil through friction against the side walls of the soil. Such piles are installed in places with high groundwater levels.
№4.Types of piles in the form of section
In the form of section piles are:
- square and rectangular .Often such are produced RC piles. This is the most popular option in most construction industries. Such piles are recommended to be used when construction goes on soft soils, they are used in the reconstruction and strengthening of the existing foundation;
- round piles, or piles, are characterized by an open bottom part, therefore during installation they are filled with soil, which increases their bearing capacity. Such piles have found application in seismically active areas;
- hollow square and round piles .These produce metal piles, as well as some reinforced concrete. The latter are used in the construction of low-rise facilities.
№5.Calculation of the number of pile supports
It is better to entrust the choice of the type of piles, their number and places of immersion by a professional, since this is a very important stage. However, it does not prevent me from knowing the basic principles of calculation. It takes place in two stages. First you need to determine the total weight of the building, and then calculate the bearing capacity of a particular pile in a particular soil.
The total building load on the foundation is calculated as the sum of the following parameters:
- the actual mass of the building .The weight of floors, walls and roof is summed. The calculation can be performed using the tabular values of the mass of basic building materials;
- snow loads .It all depends on the region of the house. For the southern regions of the country, this indicator averages 50 kg / m2, for the central - 100 kg / m2, for the northern - 190 kg / m2;
- payloads .This includes the weight of the furniture to be used and the people who live there. In order not to bother with calculating the mass of all items of furniture, you can use an average value of 150 kg / m2.
The data obtained are summarized and multiplied by a safety factor of 1.2.
The bearing characteristics of the pile depend on the type of soil. Ideally, it is necessary to conduct geodetic studies in order to accurately know the carrying capacity of the soil, but if this is not possible, you can use tabular data - you just need to know the type of soil. For example, the bearing capacity of dry clay of average density is 2.5 kg / cm2, and dense coarse sand is about 6 kg / cm2.
Each type of pile has its own bearing capacity.
For example, we need to build a 2-storey house from a timber with dimensions 10 * 8, we will use screw piles of 89 * 300 mm. If the house is located in the central lane, then the snow load will be equal to 10 * 8 * 100 = 8 t / m2.The payload of each of the floors is 10 * 8 * 150 = 12 t / m2, i.e.for the whole house 24 t / m2.The mass of the house itself is approximately 44 tons. The cumulative load( 44 + 24 + 8) * 1.2 = 91.2 tons. Suppose the soil is soft plastic, the piles will sink 2.5 m( their bearing capacity is 5 tons), then 91.2 / 5 = 18.24 will be needed, i.e.19 piles.
The depth of immersion of an pile is selected based on the type of soil. For a stable dense soil, 2.5 m long piles are usually sufficient. If the soil is unstable, the pile length must be such as to reach a more dense soil layer.
Screw piles are often used in private construction. They are available in different diameters: :
- 57 mm - such piles are suitable for creating the foundation for light fences;
- 76 mm - piles for the construction of heavier fences( for example, from corrugated boarding), as well as light structures( gazebo);
- 89 mm - piles for the construction of country houses, small private houses, household buildings. Such a support, on average, withstands 3-5 tons;
- 108 mm - an excellent option for the construction of private houses of any type, withstand from 5 to 7 tons.
The distance between the piles is calculated for each individual project. It is not recommended to make the distance between the supports more than 3 m for frame houses, and more than 2 m - for buildings made of foam block and gas block. If there are strong winds in the region, the distance between the supports should be no more than 2.5 m.
We emphasize once again that when it comes to such a serious matter as a foundation, it is better to carry out the most accurate calculations and not save on building materials and equipment.