There is no need to hire additional, expensive special equipment; a regular mini drilling machine capable of screwing in a pile of the required length will do. The design of the pile is such that it can be screwed in without much effort and in one go. In this case, the integrity of the soil is not compromised and it is not loosened.

O determine the predominant type of soil on the site.

The bearing capacity of different types of soil is given below (from wet... to dry):

sands large to medium size → 4.4… 4.8 kg/cm2

sands small → 3.7… 4.4 kg/cm2

sands dusty → 3.1… 4.2 kg/cm2

sandy loam plastic → 1.7… 3.0 kg/cm2

loams semi-solid → 1.9… 2.2 kg/cm2

loams tight-plastic → 1.4… 2.2 kg/cm2

loams soft plastic → 1.0… 1.7 kg/cm2

clay semi-solid → 1.6… 2.0 kg/cm2

clay tight-plastic → 1.5… 2.0 kg/cm2

clay soft plastic → 1.1… 1.7 kg/cm2

* An increase in soil moisture reduces its bearing capacity several times. Only coarse and medium-sized sands do not change their properties with increasing humidity. Excessive soil moisture is most likely associated with high groundwater levels.

To find out the bearing capacity of the soil It is not necessary to seek help from geologists; if you build a house yourself, you can determine the type of soil by eye. To do this, you need to go 2 m deep with a simple earth drill or shovel. In this case, it will immediately be clear what kind of soil is at this depth and how moist it is. It is not difficult to distinguish sand from clay: individual grains of sand are clearly visible in the sand, and when you rub the sandy soil with your palms, they are clearly felt. Coarse sand has a particle size from 0.25 to 5 mm, such particles are clearly visible to the naked eye, and medium-density sand has a grain size of up to 2 mm. Sandy loam contains no more than 10% clay particles; in a dry state it crumbles; if you roll a ball out of it, it will crumble with light pressure on it. Loam contains from 10% to 30% clay particles and has greater plasticity than sandy loam. If you make a ball out of loam and crush it, it turns into a flat cake with cracks along the edges. Clay is the most plastic soil; if you crush a ball made of clay, it will turn into a cake with no cracks at the edges.

Soil moisture You can also determine it by eye. If the dug hole or drilled well is dry (moist, but without puddles), then the soil can be considered dry. If water accumulates at the bottom of the well after some time, then the groundwater level is close and the soil should be considered saturated with moisture. The moisture content and plasticity of clay can be determined as follows: if the shovel enters the clay easily and the clay adheres well to the shovel, then it is plastic and wet. Otherwise it can be considered dry.

Soil density different at different depths. The soil located deep underground will be dense because the layers of soil located above press on it. When drilling a well, the soil excavated to the surface of the earth becomes loose and has a bulk density that is much lower.

When calculating bearing capacity soil located at a depth of approximately 1 m or more can be considered dense. Soil research does not always happen, and even with professional house design, such data may not be available. Therefore, for simplified and approximate calculations, the load-bearing capacity of the soil is often taken to be 2 kg/cm2; this is quite suitable for the reliable installation of a heavy house on a screw foundation.

Seasonal soil freezing. We must not forget about such a very important natural factor as seasonal freezing (or thawing, for permafrost) of the soil. Data on seasonal freezing in your region can be found in standard reference books.

Pile field marking.

The next step is to create (mark) a pile field according to the required load-bearing loads and the plan of the future house. When preparing the marking of a pile field, it is necessary to take into account that placing screw piles further than 2 meters from each other is not recommended according to the norms of screw foundations + it all depends on the type of construction and the type of piping, for example, for a bathhouse or a summer kitchen you can increase the step to 2.5-3 meters without severe damage to the load-bearing capacity of the foundation.

To begin with, the markings can be drawn on a piece of paper, marking future piles first in all corners of the house, then at the intersections of load-bearing walls, then check the distances between the piles and if spans of more than 3 meters are formed, add piles in the necessary places.

What is necessary for the installation of screw piles.

If piles are to be driven with your own hands, from the tool we may need:

Shovel(for small leveling of the place under the pile)

1..2 Levels on a magnet 20-30cm long (attached to the pile to control the level during tightening)

Hydraulic level at least 10 - 15m or Laser level(necessary for setting horizontal marks)

Roulette 10 - 20m (for measurements on site)

Armature or even pegs from 9 pcs. + hammer (for marking the level, twine is wound on them)

Small garden auger(to facilitate the entry of the pile for self-screwing)

Knife, gloves (optional)

S should know.

1) To begin with need to find the "first" point, from which the pile field will begin. As a rule, this is the highest point in the level. We create a second point from it, thereby creating a house line. Pay special attention to this line and try to position it as accurately as possible relative to the building plan or, for example, parallel to a fence or road. It is from this line that the entire geometry of the foundation begins.

2) If you don't have a level, you can set the level using a rope or twine fixed to reinforcement or pegs along the perimeter of the house lines. The fittings or pegs themselves must be driven in “out” beyond the perimeter of the house, this is necessary so that they do not interfere with the screwing process. If special equipment will be screwed, it is also necessary to develop a strategy for moving it along the pile field relative to the tensioned twine. If the area of ​​the house is large, the twine will have to be tied in stages to allow the machine to approach the site of the future pile.

3) It is possible prepare shallow holes using a small garden drill, this will make it easier to guide the pile along the desired path.

4) If it’s winter outside, platform for installation of piles No need to clear snow! A cap of snow holds back freezing, so it will be easier to tighten.

5) As the piles are tightened, tie with twine, thereby creating a level for new piles, but we must not forget that the strapping will be slightly lower than the platform (head) of the pile itself!

6) The level of the pile at the highest point of the site, above the ground surface, should be such that even with strong seasonal heaving of the soil pile head always been 15-20 cm above the surface.

7) It is better to screw in the pile in one go, when twisting, it is not recommended to “adjust” the level by twisting it back. The main rule is to measure seven times...

8) After driving the last pile, you can begin building the house immediately; there is no need to “let the foundation settle.” If wooden construction is planned from lumber (logs, beams, panel house, frame house), then the role of the strapping will be played by the lower strapping crown of the house, which is placed directly on the heads of the screw piles and is attracted to them. No other strapping, including metal, not required. Now you know the basic rules about how to How to tighten a screw pile. If you encounter any difficulties related to the installation of a screw foundation, our specialists will help and suggest the right solution!

If you have any questions, you can ask them in the comments or

in the Questions and Answers section, or contact us using any other contacts.

Technologies

Hot dip galvanizing (DIN EN ISO 1461, former DIN 50976)

To be galvanized After final preparation, the screw piles are dipped into molten zinc (approx. 450°C). As a result of chemical reactions, various alloys are formed that are firmly connected to the steel base. These alloys are separated from the layer of “pure” zinc. Depending on the reaction rate, steel composition, duration of stay in the bath, cooling process, etc., the resulting alloy “rises” to the surface.

Surface Appearance varies from light glossy to dark gray matte, while the thickness of the zinc layer and its resistance to corrosion remain unchanged. Subsequently, minor corrosion may occur in damp environments, primarily on freshly galvanized surfaces, in the form of deposits of zinc hydroxide carbonate (so-called “white rust”). However, it does not have any negative effect on the anti-corrosion coating. The cut surfaces should be treated with zinc paint (G4 Catalog). According to DIN EN ISO 1461 the average coating thickness is at least: 45 microns for materials with a thickness of less than 1.5 mm 55 microns for materials with a thickness of 1.5 mm to 3 mm 70 microns for materials with a thickness of 3 to 6 mm.

Damage to zinc coating in the process of cutting, drilling holes, etc., it does not lead to further corrosion, since the zinc adjacent to the damage site dissolves under the influence of atmospheric oxygen and moisture and forms a brownish layer of zinc hydroxide on the uncovered cut surfaces. The chaotic movement of zinc ions protects exposed surfaces with a layer 2.0 mm wide.

Carbon steel ISO630

This standard applies to carbon steel of ordinary quality, intended for the production of hot-rolled products: long-rolled, shaped, thick-sheet, thin-sheet, wide-band and cold-rolled thin-sheet, as well as screw piles, ingots, blooms, slabs, sutunki, rolled and continuously cast billets, pipes, forgings and stampings, tape, wire, hardware, etc.

Fe360 A: Quality category: A B C / Rolled thickness, mm: Up to 16 St. 16.
Mass fraction of elements (no more than %): Carbon 0.20 0.18 0.20 0.17 0.17 / Phosphorus: 0.060 0.050 0.050 0.045 0.040 / Sulfur: 0.050 0.050 0.050 0.045 0.040 / Nitrogen: 0.009 0.009 0.009 / Degree deoxidation: E CF / Mass fraction of Manganese no more than 1.60%, Silicon no more than 0.55%.

Technologies

PVC coating

PVC coating or called polyethylene, this is a polymer layer that has proven itself to be an excellent protection for metal structures. The layer thickness reaches 2 mm. After completing the production of welded mesh fence, the product is evenly heated for approx. up to 300°C, after which it is lowered into a container filled with a PVC polymer composition made of polyethylene, pre-painted using paints in the desired color. Particles of pigment (paint) and polyethylene, sticking to the hot metal, form a thick layer. Then the process of polymerization (“solidification”) occurs, as a result of which the surface of the metal is tightly covered with a layer of monolithic coating, which prevents any unfavorable conditions, damage due to deformation, and especially the activation of corrosion reactions due to contact with water.

Spot resistance welding

Technology basis this is the thermal effect of electric current according to the Joule-Lenz law and the compression force of the parts being welded. During the welding process, current passes from one electrode to another through the metal of the workpiece. Electrodes for resistance spot welding are made from alloys with high electrical conductivity so that the resistance in the electrode-workpiece contact is minimal. Therefore, at the points of contact between the fence rod and rod, the greatest heating occurs due to the greatest value of electrical resistance. Heating and melting of the metal under the influence of electric current leads to the formation of a cast core of the weld point, the diameter of which is usually 4-12 mm.

Strength welding connection of fence rods - high, good appearance at the joints of the mesh panel. Joints obtained by resistance welding are not subject to aging; the structure of the metal in the welding zone remains virtually unchanged, with the exception of a slight increase in grain size.

A pile foundation is a structure of supports immersed in the soil and a grillage (strip reinforced concrete monolith or slab) located along the perimeter of the future structure. To build this type of base, you need to make the appropriate calculations and draw up a project, because a pile field, the structure of which at first glance seems simple, has many nuances.

General information

Thanks to its undeniable advantages, including strength and long service life, foundations on piles are especially popular among professional builders and beginners. The use of such bases is especially effective:

• During construction on unstable weak soils prone to seasonal swelling;
• When laying a supporting structure on heavy soils, in order to reduce the number of excavations, reduce physical, time and financial costs.

One of the most important elements of the pile base is the pile field (made of screw piles, bored supports, etc.), which is the area of ​​the site on which the supports are placed in accordance with the project. The durability of the structure being built depends on how well the calculations and markings are carried out.

In the support field, piles can be buried not only in rows, but also in a checkerboard pattern. The installation of supports is carried out in such a way that the distance between the external design border of the grillage and the center lines of the supports is similar to the diameter of the pile in plan.

Calculations

Calculation of a pile field involves calculating the number of piles required to construct the foundation. The appropriate number of supports is determined using:

• Calculation of the total load on the basis of all elements of the future house;
• Determination of the load-bearing force of each support;

The total load includes not only the mass of the walls and roof of the future building, but also the weight of finishing, building materials, and interior items.

Having made the calculations and received a specific value, you should begin to calculate the operational load on the structure. To simplify the task, just refer to GOST data. The operating load is equal to:

• 200 kg per square meter - for industrial buildings;
• 150 kg per square meter - for residential buildings.

The next stage of calculations involves determining the snow load in the cold season. The indicator depends on the region in which the site being built is located. The standard weight (layer of snow per 1 square meter) is multiplied by the roof surface area.

Ultimately, all the data obtained are summed up and multiplied by the reliability indicator (1.2).

To calculate the load-bearing capacity of each individual pile, it is worth taking into account the qualitative characteristics of the soil located on the site, since it is almost impossible to determine the real supporting force based on the material used to construct it. The load-bearing power of a pile often turns out to be greater than the resistance force of the soil, and therefore the properties of the supports are determined by the soil into which they are buried.

Having received all the necessary values, the total load from the building is divided by the load-bearing capacity of the pile. The result is the number of supports required to construct the basic structure.

When the calculations are completed, they begin to draw up an executive diagram. It depicts a pile field (drawing), outlines the order of placing piles along the boundaries and load-bearing walls of the building.

Making markup

One of the main stages of constructing a foundation on supports is laying out the pile field. This procedure consists of three phases:

• Transfer of the contours of the reference field (base lines) to the development area in accordance with the project;
• Marking immersion sites for each product;
• Setting the zero line of the pile field (the marker along which the piles are leveled after being buried in the soil).

To carry out the breakdown, wooden pegs are used (steel reinforcing bars can also be used) and strong twine (wire, nylon thread).

The first pin is installed at the location of the corner pile, since it is impractical to start marking from the internal supports. From the hammered peg, use a tape measure to measure the size of the first side in order to hammer in the second pin. A string is pulled between the pegs. The remaining sides are marked using a similar method.

During marking, a document called an axle layout act must be drawn up. All diagrams and drawings are attached to it, notes are made about the distance between the piles, the height of the supporting elements and the position of the lines.

Reference field device

The actual construction of a pile field begins with the preparation of the site, building materials and equipment. The following preparations need to be made:

• Deliver all equipment to the construction site;
• Transport, unload and stack the required number of piles in a certain place;
• Dig a pit (if its development is planned).

Upon completion of preparation, the supports are buried in the soil using a pile driver. It is worth remembering that the as-built diagram of a pile field is an example and indicator in accordance with which all work is carried out, so there should be no improvisations. The design of the reference field is carried out in several steps:

• The driving machine is placed at the driving point, the supporting element is secured using a winch and moved to the driving point;
• The excess weight is removed from the pile, it is lifted and placed in a vertical position at the immersion site;
• The pile is fixed on the mast of the pile driver and connected to a special hammer. The position of the support is checked again - it must be strictly vertical. If driving is done at an angle, then the slope must correspond to the norm;
• The fixed product is struck with a piledriver hammer. This manipulation lasts exactly until the pile enters the ground to the mark corresponding to the design and as-built diagram.
• After driving the support, the pile driver moves to the next designated location.

Each new pile is buried in the same way.

Breakdown of a pile field in theory:

On practice:

We make the casting in such a way that the bottom board is the level to which we will place all the pillars, and the second is the top level of the grillage. We align both boards of all castoffs at “0” horizontally relative to each other. That is, the bottom board for the posts of one cast-off should be on the same level as the bottom board of the other cast-offs. The same goes for the top boards for the grillage.

Marking a columnar (pile) foundation

We stretch the strings so that their intersections are the centers of the pillars (wells). We find angles of 90⁰ for a rectangular foundation using the Pythagorean method by constructing a triangle with dimensions 3x4x5m. Read how to do this in the article: Rules for constructing a rectangular foundation. The distance between the strings is equal to the distance between the pillars according to the project. The distance from the cast-offs to the foundation contour is 3 meters.

At the intersection of the strings we lower a plumb line, which will show us the centers for drilling holes under the pillars.

We insert pegs at the plumb points. And we temporarily remove the strings so that they do not interfere with us while drilling wells.

We drill holes for pillars.

The next step is to pull the removed strings to bring all the pillars to a common level. This method has several features. Since the strings by which we found the centers of the pillars (wells) will interfere with us during the formation of the pile, we will no longer need such a marking arrangement. We will need to move the strings by a distance equal to the radius of the pillar (using a tape measure), that is, the strings will already pass next to the pillar, and will serve as a guideline for the general level of the piles. How to do this, see the figure.

We bring the pillars to the general level according to the markings. The level, we remind you, is displayed at “0”.

Grillage marking

The next operation is marking the grillage. For this purpose, we will use the old markings for the centers of the piles.

And so, we have a self-tapping screw along which strings were pulled to find the centers of the piles.

From this self-tapping screw, using a plumb line, we make a mark on the top cast-off board, intended for the level to which we will place our grillage.

From the mark in different directions we mark the same distance, equal in total to the width of the grillage. In our example, we will make a grillage 40 cm wide, therefore, we measure 20 cm in different directions and screw in the screws. That is, we will get 2 self-tapping screws for the outer and inner contour of the grillage.

We make markings for the grillage. We stretch the twine onto the screws of the top cast-off board.

We bring out the grillage along the strings.

What is important to know when marking pillars and grillage using the method described in this article.

Task. It is necessary to build a grillage measuring 6x8m and 40cm wide. It is necessary to calculate the dimensions of the rectangle for the piles.

Solution. For this grillage, we will need to build a marking in the form of a rectangle with dimensions of 6 by 8 meters, which will be the outer contour of the grillage.

In our example for the pillars, we string strings that will run through the center of the piles. The piles, in turn, should pass exactly in the center of the grillage. Therefore, to build a rectangle for the piles, we need to retreat from the sides of the 6x8m rectangle by an amount equal to half the width of the grillage, that is, in our case, 20 cm from each edge. As a result, the rectangle built for the pillars will measure 5.6 m by 7.6 m.

Let's see how it will look in the picture.

From the author

In this article we looked at one of the ways to mark a columnar foundation. There can be many options for marking. The main thing is to observe the dimensions, level and right angles.

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This article provides detailed instructions for manually installing a foundation from bored piles. We will consider all stages of creating a foundation - from its design and marking to pouring piles and tying them with a reinforced concrete grillage.

Independent foundation design

The first stage of arranging any pile foundation is its design, during which it is necessary to determine the load-bearing capacity of the reinforced concrete support and the total loads on the foundation, and based on them, calculate the required number of piles for building a house.

Important: the load-bearing properties of a pile are always determined “by the soil”, since the load-bearing characteristics of concrete as a material exceed those of the soil. For example, 1 sq. cm of M100 concrete can withstand a standard load of 100 kg/sq.cm, while 1 cm2 of clay soil, which is prevalent in the Moscow region, holds no more than 6 kg/cm2.

Fig 1.1

To find out the load-bearing properties of the soil, it is necessary to conduct geodetic surveys at the construction site. During their implementation, geodetic wells are drilled, from which soil samples are taken for laboratory analysis. The price of the service depends on the depth of soil development - from 2 to 3 thousand per 1 linear meter of well (the price includes the cost of laboratory work).

We offer you an average calculation of the load-bearing properties of piles based on clayey soil common in Moscow. The table shows the characteristics of piles with a diameter of 15-40 cm typical for individual construction.

Figure 1.2

To determine the number of piles in the foundation, you need to calculate the total mass of the building, which is done by multiplying the area of ​​the structural elements of the building by the standard weight of building materials given in the following table:

Rice. 1.3

The following loads are added to the resulting mass of the building:

• Useful operating load - 100 kg per sq.m. floors of the house (ground and interfloor);
• Snow load on the roof (depending on the region of construction).

Rice. 1.4: Map of snow loads of the Russian Federation

The total sum of loads is multiplied by 1.2 (safety factor), after which the result is divided by the load-bearing capacity of one pile. This determines the required number of supports in the base.

The pile placement scheme is drawn up as follows:

• The minimum distance between supports is 1 m, the maximum is 3 m;
• It is necessary to have piles at the points where the walls join at the corners of the building and at the junctions of the internal and external walls;
• The supports are deepened below the depth of soil freezing in a given region (to avoid negative loads from soil heaving).

Rice. 1.5: Map of soil freezing in Russian regions

Preparatory work

Before starting the installation of the foundation, it is necessary to purchase the required consumables - concrete, reinforcement and planed boards for installing the formwork under the grillage. The standard consumption of concrete and reinforcement for typical configurations of bored piles is shown in Figure 1.1

To build a bored foundation yourself, you will need the following tools and materials:

• For marking - reinforcing bars, planed boards and bars, construction cord or twine, self-tapping screws, level, tape measure;
• For the installation of reinforced concrete piles - a concrete mixer, shovels, a hand drill, buckets, rolled roofing felt, tape, a wheelbarrow for removing soil;
• To create reinforced frames: welding machine, grinder, reinforcing bars (corrugated, 12-15 mm in diameter, and smooth, 8-12 mm in diameter);
• For the grillage - ready-mixed concrete in the required quantity, boards for formwork, hacksaws, nails and screws, electric drill, wire, waterproofing material for the grillage to cover after pouring.

Important: Initially, it is necessary to prepare the construction site - remove surface vegetation, debris, stones and boulders that may interfere with the work. If there is a sloping terrain, the site is leveled to one level.

Do-it-yourself foundation marking

To mark the base, it is necessary to knock down stripping boards from planed boards and beams. The structure consists of two horizontal belts, the first of which is used to lay out the zero level of the piles (their height), the second - to break out the upper edge of the grillage.

Rice. 1.6

Initially, the base lines of the foundation (the contours of the walls of the building) are marked - the distance is counted from the landmark (fence or site boundary) and the cast-off of the first wall is installed, a string is pulled between the boards (the thread is fixed using a self-tapping screw screwed into the board).

An adjacent wall is marked perpendicular to the laid contour. The right angle is checked using the Egyptian triangle (a distance of 3 and 4 meters is given on intersecting laces, a mark is made with electrical tape and the length of the diagonal is measured - at the correct angle its length is 5 meters).

Rice. 1.7

Next, the two remaining walls are marked in the same way. At a distance of the thickness of the grillage, a second cord is installed on the cast-off, defining the internal contour of the walls. The positions of the piles are marked according to their design distance from each other - casting boards are installed and a plumb line is lowered from the intersection of the string, under which a reinforcing peg is driven in, which determines the installation location of the pile.

DIY installation of bored piles

After marking the foundation, the stretched twine is dismantled and only the pegs are left in the places where the piles are arranged. The technology for creating supports is implemented in the following sequence:

• Using a hand drill, wells for piles are developed. It makes sense to go through all the wells at once, so that in the future you can fill the supports with concrete in one go;
• A cylinder equal to the diameter of the pile is formed from rolled roofing felt, which is fastened with tape. The cylinder in this case acts as the pile formwork, so its height should be equal to the full length of the reinforced concrete structure (if necessary, protrude from the well). Once created, the formwork is placed inside the cavity;

Rice. 1.8

• Reinforcing bars in the amount of 4-8 pieces are inserted into the wells (depending on the diameter of the pile). The rods are immersed in the ground so that the soil securely fixes them. The length of the reinforcement should be 30-40 cm greater than the length of the pile, protrusions are necessary for joining with the reinforcement frame of the grillage;
• A concrete mixture is poured into the prepared wells (concrete grades M200 or M300 are used). You can prepare the mixture yourself using a concrete mixer or order ready-mixed concrete in the required quantity;

Rice. 1.9

• After pouring, the concrete is bayoneted with reinforcement, which is necessary to remove air cavities formed in it from the mixture.

Important: Having formed the concrete body of the piles, it is necessary to wait 20-30 days before subsequent work, during which the structures gain standard strength.

Self-installation of reinforced concrete piping

Before arranging the grillage, it is necessary to restore the base lines dismantled for installation of piles on the cast-off. In this case, the twine is stretched along the upper horizontal belt, which is responsible for the level of the grillage.

Wooden formwork is installed along the contours of the trim. Initially, you need to install U-shaped load-bearing elements made of timber between bored piles, after which the outer contour of the formwork is sheathed with boards knocked into a shield.

Rice. 2.1

After forming, the formwork walls are covered with waterproofing material and work begins on installing the reinforced frame. On the reinforcement protruding from the piles, horizontal rods are fixed, raised to a height of 5 centimeters, to which pre-prepared rectangular clamps are welded.

Rice. 2.2

The side contours of the clamps in this case perform the function of transverse reinforcement. The number of longitudinal belts is selected based on the width of the grillage; for tying a standard width of 40 cm, 4 belts are used.

Important: each side of the reinforcement cage should be placed at a distance of 5 cm from the walls of the formwork, since when the reinforcement leaves the concrete body, the frame will be subject to accelerated corrosion.

The upper contour of the longitudinal reinforcement is welded to the transverse clamps. Pay special attention to strengthening corner joints - cross-joining is not allowed here.

Modern housing construction of various scales and directions (industrial, civil, commercial) has a large selection of technologies used at various stages of construction. The choice of the optimal option is carried out by designers and property owners at the stage of developing project documentation. One of the most popular ways of arranging a foundation is laying a pile field.

Pile field - what is it and why is it needed?

A pile field is the basis of a pile foundation of any type (screw, reinforced concrete, cast-in-place). When constructing the foundation, it is necessary to strictly follow the attached diagrams, since correct laying of the pile field ensures the reliability of the entire structure and its durability.

Generally speaking: specially prepared piles are installed at points on the development site, which are subsequently tied with grillages. The resulting foundation is a pile foundation. The grillage is a mandatory element for a pile foundation. It performs a connecting function between all supports and guarantees uniform load distribution between the piles. The created monolithic structure has excellent performance characteristics for any type of structure.

The pile field transfers the building load to the ground. The depth of piles is set in the project and depends on many factors:

1. Type and characteristics of soils.
2. Groundwater depths.
3. Total weight of the structure and many others. etc.

Thus, builders come to dense soil and the piles transfer stress to them. The construction of a building or structure is permissible only after proper laying of piles, tying them with a grillage and waiting for the established period of hardening and compaction.

Calculation of the number of piles

Before proceeding with the installation of piles, it is necessary to perform a number of preliminary works. The first stage is the calculation of the pile field.

This procedure provides a detailed and mathematically based analysis of the distribution of supports on a construction site. It is produced in several stages:

1. The designer determines the total load that the erected structure will create on the base.
2. The bearing capacity of 1 pile laid in the foundation is calculated.
3. The total load is divided by the characteristics of one support and thus the number of piles required for a particular object is determined.

When determining the total load arising after the construction of a building or structure, the characteristics of all building materials, the future use of the structure and the total area of ​​the building, as well as individual structural elements, are taken into account.

The GOST standards developed by design institutes and approved contain calculated load indicators for the operation of each type of building. They are determined taking into account practical experience. For residential buildings - approximately 150 kg/m2; for industrial construction - 200 kg/m2.

Specific gravity of 1 m 2 walls

When constructing several floors, it is important to take into account the number of floors and make calculations both for each floor separately and for the entire structure as a whole.

Specific gravity of 1 m 2 floors

Specific gravity of 1 m 2 of roofing

When making calculations, it is necessary to take into account the region where construction takes place. Each region has unique snowpack averages. When developing a project for a pile field, it is necessary to calculate the loads from the pressure of the snow cover, based on average statistical observations for a specific area.

The average snow cover weight is given in the table:

To obtain the specified data, it is necessary to multiply the roof area of ​​the building by the mass of the snow cover. 20% is added to the final result - this is an additional parameter called the reliability coefficient.

Designing a pile field requires special attention to calculations. It is necessary to achieve the optimal combination of the number of supports, their strength and depth. For these works, it is important to have accurate data from geological and geodetic pre-design tests.

As an example, the table below contains indicators of the bearing capacity of soils and screw piles:

Soil type	Design soil resistance *, kg/cm2		Load-bearing capacity of a screw pile, kg
			VSG-1 73/250		VSG-1 89/300
	dense	Wed tight	tight	Wed tight	tight	Wed tight
Coarse gravelly sand	13.0	12.0	6378	5888	9185	8478
Medium sand	12.0	11.0	5888	5397	8478	7772
Fine low-moisture sand	5.0	4.0	2453	1963	3533	2826
Fine sand saturated with moisture	3.0	2.0	1472	981	2120	1413
Dry sandy loam	5.0	4.0	2453	1963	3533	2826
Sandy loam saturated with moisture	3.0	2.0	1472	981	2120	1413
Dry loams	4.0	3.0	1963	1472	2826	2120
Loams saturated with moisture	3.0	1.0	1472	491	2120	707
Dry clays	6.0	2.5	2944	1227	4239	1766
Clays saturated with moisture	4.0	1.0	1963	491	2826	707

And in the end, after receiving all the calculated data, they move on to determining the number of supports for a specific project. To do this, the total mass is divided by the load-bearing capacity of one pile (as mentioned above).

Pile field marking

The pile field diagram serves as the basis for outlining the project. These works are carried out by qualified surveyors.

The drawing determines the position of the entire structure and each pile separately on the building site. A geodesist engineer, using special equipment (electronic total station, GPS systems), determines their actual location on the site and secures them with reinforcement with an accuracy of 1 cm. Depending on the complexity of the structure and accuracy requirements, this work can also be performed with a tape measure.

The procedure for setting out (laying out) a pile field includes several stages:

1. Bringing field baselines to the construction site.
2. Breakdown of the location of each pile on the site.
3. Determination of the zero level of the pile field (the mark at which the supports should reach after they are laid).

It is important to securely secure each point and ensure their safety. Otherwise, you will have to call specialists again.

For convenience, it is recommended to use the following method: secure the foundation axes to cast-offs behind the building site. Then a string is pulled between them - the intersection point of the two threads is where the pile is installed. This way you will ensure their safety when moving people and equipment around the site.

Be sure to use the approved pile field plan - this way you avoid violations and guarantee the legality of the work performed.

Installation of a pile field

After completing all the design work and subsequent securing the points of the pile field on the site, you can proceed to installation.

In practice, piles are arranged in the form of several figures:

1. Pile bush - a small number of piles located nearby. The grillage in this case can have an aspect ratio of 1:5. The best option for tall structures and columns.
2. Pile strip - supports are arranged in a row. Suitable for elongated walls.
3. Pile field is a large number of piles evenly distributed on the site. For residential and industrial buildings.

Before work, all necessary equipment must be delivered to the site. It is imperative to have at your disposal a sufficient number of piles with the required characteristics. Before laying the supports, a vertical layout of the building site is carried out.

If the piles you have chosen are screw ones, then you can “screw them in” on your own using special devices for such work.

A pile driver is used to drive reinforced concrete piles. In this case, the work includes the following steps:

1. The machine is installed in the place where the pile is being beaten, and the pile is dragged to it.
2. After slinging the pile, it is brought to a vertical position. Maintaining verticality ensures the strength of the structure and reduces the risk of destruction of the pile and the operation of the pile driver.
3. After docking with the piling hammer, the pile begins to be driven into the ground to the required depth. The design specifies the estimated failure of the pile - the depth at which it stops going into the ground.
4. After driving all the supports, they are leveled to the set height. Most often this is done by workers using jackhammers.

When laying each pile field, a drawing must be developed. This document serves as a kind of instruction for carrying out the entire complex of work. Following these calculations guarantees that the entire structure will achieve the designed parameters. Therefore, it is especially important to correctly install the pile field.