The foundation device is the initial and most important part of the construction work. The reliability and durability of the building largely depend on the strength and quality of this structural element. An improperly designed and installed foundation, without taking into account the design of the building and the characteristics of the soil on the site, can cause the destruction of the house. That is why this operation must be approached with all responsibility.

Particular attention should be paid to soils. On their different types, the same structural solution of the foundation will have different strengths. For example, a tape base will stand for centuries without problems on rocky soil or on black soil, and on clay soils it may well “float away” with a high location of groundwater. It is about clay soils and the features of building foundations on them - further.

Features of clay soils

The main feature of clay soil is that it does not hold its shape at all. A few "drops" of water are enough and the clay spreads. We have all dealt with this stuff at some point. Its extreme plasticity allows you to make a large number of different products from it, however, in construction this is not an advantage, but a disadvantage. Due to the increased plasticity, clay soil cannot act as a full-fledged support for the building, which, when the soil is washed out from under the foundation, can contribute to the formation of voids. They, in turn, can cause subsidence of the basis. Which will lead to the destruction of the building. That is why the construction of a house on such soils should be accompanied by their in-depth analysis by specialists who should issue their opinion on the possibility of building a structure.

Clay soil is different, depending on the content of clay in it:

1. Starting at 30%, soil is considered clay. Due to the high moisture content, such soil is practically not suitable for construction. The complexity and high cost of the foundation built on it makes the structure very expensive. The fact is that when freezing, the moisture contained in such soil tends to expand, which in turn can damage the foundation.

2. Mixes of sand, clay and stone. Of all clay soils, the latter is the most suitable for construction. Due to the stone, it perfectly holds its shape, does not float, which makes building on it not very difficult and quite strong.

3. Other types of soil. There are also:

Sandy loam - a type of soil that contains sand and clay, the latter not exceeding 5%;

Loam - soil consisting of sand and clay, in which the latter is not more than 10%.

Sandy loams and loams, like clay, belong to the category of unreliable soils, the behavior of which depends on many factors. In each individual case, there is a need for a thorough analysis of the state of the soil to make a decision on the design of the foundation.

There are two main types of clay:

1. Red clay. This material contains a large amount of sand. It is because of this that it perfectly absorbs moisture and does not hold its shape well. Soils containing red clay are extremely unstable and very often subject to destruction and structural changes.

2. Blue clay. It has better strength characteristics. Practically does not pass moisture, which can accumulate on its surface.

Clay soil. What foundation is right for her

The construction of foundations on clay soils cannot be carried out without special preparation. If possible, it is better to move it to another place, if not, to involve specialists for help. It should be aware that such construction will be not only difficult, but also costly.

Strip foundation on clay soil

On clay soil, a strip foundation is acceptable, however, it will have a slightly different structure compared to the same type for other types of soil. The advantages of the tape basis are:

1.High reliability in compliance with all technology requirements.

2.Excellent strength and waterproofing.

3. Suitable for almost any type of buildings and materials from which they are built.

4. The possibility of building a foundation on clay soil with your own hands in a short time.

The disadvantages of this type of foundation are as follows:

1. High costs of time and money for earthworks.

2. Large mass and high cost of materials.

Formwork for strip foundation

There are several options for arranging such a foundation:

The first scheme for the construction of a strip foundation on clay soils involves the construction of a special pillow. In a trench dug under the base tape, several layers of sand and gravel are laid alternately. The thickness of each of them should be at least 18-22 cm. After filling the next layer, it is poured with water and carefully compacted. Such a pillow falls asleep to zero level. Then a base of large stone or brick is built on it. From above, the plinth is covered with several layers of PVC film or roofing material.

The second option for building a foundation involves filling only half the depth of the pit with a sand-gravel mixture. The pillow is carefully compacted and leveled. Then one layer of brickwork is laid on its surface. After the solution dries, a formwork is constructed for pouring concrete to the required height. Formwork boards must be treated with a special antiseptic and covered with a layer of tar. The formwork is set to the required height of the foundation and poured with concrete. After that, the foundation is leveled and a layer of waterproofing is laid on top. For the latter, you can use a dense PVC film or roofing material.

The third version of the basis involves the use of flat slate for formwork. Formwork assembled from sheets of roofing material is immersed in a dug pit. The distance between the soil and the formwork is filled with gravel. Inside, half of the tank is filled with a mixture of sand and gravel and carefully compacted. Lastly, concrete is poured in layers of no more than 15 cm, which must be compacted with a special construction vibrator until cement milk appears on its surface. After cooling, the foundation must be covered with waterproofing.

If possible, it is desirable to open its outer planes with bituminous mastic before backfilling the distance between the ground and the base and cover it with waterproofing. The filling is done with gravel.

Pile foundation on clay soil

A pile or column foundation is the simplest and most balanced solution for building on clay soils. Due to the need to drill special wells and the corresponding use of special tools and equipment, this type of basis can hardly be called the cheapest. However, its durability on unstable ground makes it the most acceptable.

Among the advantages of such a foundation are the following:

1. The minimum required amount of materials and their availability.

2. Minimum shrinkage of materials.

3. Simplicity in execution.

4. Possibility of installation in areas with the most difficult soil composition.

He has one drawback - the need to use special equipment.

The device of such a foundation at first glance is not too complicated. Work procedure:

1. Depending on the design of the building, special holes with a diameter of 200-300 mm are drilled under each bearing plate. The depth in each individual case is determined by a specialist. It should be below the freezing point of the soil.

2. A layer of gravel is poured at the bottom of the well, after which an asbestos-cement pipe is lowered into it. Concrete is poured inside.

3. Before pouring, several reinforcing bars are inserted into the pipe to reinforce the structure.

4. The pillars are installed at the intersection of load-bearing walls and at the corners of the building. The installation step of the supports should not exceed 2 meters.

There is another foundation on clay soil, the scheme of which is similar to the previous one - the so-called pile-backfill. It is built using a slightly different technology, and it can be used in places with water-saturated soil. It is worth noting that such a foundation will be much cheaper than a pile foundation.

The technology of its construction is quite simple:

1. In places where, according to the project, supports should be installed, a layer of soil is removed and holes are dug 0.5 m deep and 0.4x0.6 m in size.

2. A mixture of sand and gravel is poured onto its bottom, which is compacted and watered. The filling is carried out in layers to the ground level, constantly tamping.

3. Then concrete blocks are laid on the prepared pillow. For this purpose, products of a standard size of 0.2 x 0.3 x 0.5 m or 0.3 x 0.3 x 0.5 m are used.

4. For the installation of one support, as a rule, 2 concrete blocks are used, interconnected with a solution. The sides of the blocks are treated with an antiseptic, and a layer of roofing felt or PVC film is laid on the upper part to provide waterproofing.

The stability of such a basis lies in the fact that water cannot penetrate into the lower layers of the embankment, since they contain air. Although water penetrates into the layers of clay soil during autumn rains or spring floods, the lower filling remains absolutely dry. Due to this, when frost sets in, the filling does not expand, which eliminates the movement of the basis and distortions in the geometry of the entire building.

If it is not possible to buy concrete blocks, you can cast them from concrete on site. To do this, install the formwork of the required height and pour the solution. This should be done in layers, constantly vibrocompaction. After that, you need to process the finished pillars in the same way as concrete blocks.

Building a foundation on clay soils often presents a range of challenges, with the combination of clay soil and closely spaced groundwater being the most challenging. Wet clays belong to the V group of soils in terms of frost heaving deformation; when frozen, they are able to exert enormous pressure on the base and walls of the foundation. If the building is not designed correctly, then cracks, failures and destruction of the house are possible. Therefore, when building a capital structure on clay soils, it is imperative to contact the design organization. If we are talking about how to build a foundation on clay for a small house, bath or garage, you can do it yourself, given the recommendations given in the article.

Choosing the type of foundation for clay soil

First of all, you need to determine several features of the soil in your area:

• The content of clay particles in the soil;
• Soil moisture;
• The depth of soil freezing for your region;
• Ground water level.

The composition of the soil is determined as follows: you need to take a certain amount of soil in your hand, knead it and try to roll up the “sausage”. It can't be done with sand. Loams acquire the necessary shape, but soon crack and break up into separate pieces. If a whole plastic “sausage” is obtained from the soil, this is clay, one of the most difficult soils for construction. To determine the humidity, it is necessary to leave the soil for some time in the air. If drying takes several hours, then the soil is wet. It is these soils that are most susceptible to frost heaving.

The groundwater level at the site can be determined by a well or a pit can be drilled. The depth of soil freezing is determined according to reference data, for this you can use the table:

If the groundwater level is significantly below the freezing depth of the soil, then after that it is possible to build a shallow one. At the same time, it is recommended to make the base of the foundation wider than its upper part in order to increase the area and reduce the specific load from the soil. Under the sole of the foundation, it is necessary to erect a thick sand cushion - it will serve as a kind of shock absorber, and will also allow you to remove excess moisture from the foundation. At the same time, the foundation must be waterproofed from the outside with high-strength roll materials - this will prevent clay from sticking to the foundation and shifting a large mass of soil along with the foundation when it freezes. Also, it will not be superfluous to warm the soil around the foundation by creating a blind area. It must be borne in mind: if the project is designed to heat the basement, it cannot be frozen - this can lead to serious deformations.

With a close location of groundwater, a device with deepening of piles to a considerable depth is necessary. At the bottom of the piles, it will be necessary to make an expansion that will not allow the forces of frost heaving to push the foundation out of the ground.

Recently, the technology of steel screw piles is gaining more and more popularity. Screw piles are a hollow metal pipe with a pointed end, on which the blades are located. When the pile is screwed in, these blades are drilled into the ground, which contributes to the advancement of the pile in depth. The blades of the piles do not loosen the soil, unlike concrete piles, so the soil around the helical steel piles retains its initial compaction.

Technology for making a foundation on clay using screw piles

1. Site preparation is reduced to geodetic exploration, calculation of the required number of piles and the approximate depth of their installation. Screw piles can be installed at different depths, which is convenient for areas with a strong slope or uneven type of soil. Piles must be installed in the corners, as well as at the intersection of the walls. In addition, piles must be placed along load-bearing walls at a distance of at least 2 meters. After calculating the number of piles according to the drawing, the specific load of the building on each pile is checked, if necessary, the location for installing additional piles is determined. The site is cleared of construction debris and foreign objects. The soil on the entire area of ​​the building is cut off. Marking is carried out, marking the places of installation of piles.

   

2. Screw the first corner pile. This can be done both manually, using a lever, and using a special mechanism. Clay soils are quite heavy, so it is better to choose the second option. When screwing a pile by hand, it is necessary to check its verticality along the slope all the time. The slightest deviation can cause the building to skew during operation.

   

3. Subsequent piles are screwed in the same way. In this case, it is necessary to check the pile location plan from time to time. Screwing of piles is carried out until they reach the calculated depth, that is, below the depth of freezing of the soil and the level of groundwater. If the depth of the pile is not enough, it is built up.

   

4. After screwing all the piles along the hydraulic level, mark the floor level of the first floor. As a rule, it should not be lower than 50 cm for residential buildings and 30 cm for a gazebo or outbuilding. All piles are marked at this level and the excess length is cut off with a grinder.

   

5. To give them greater strength, piles are filled with concrete of grade not lower than M200. With a significant depth of piles, it must be compacted during pouring with a reinforcing bar, piercing the thickness of concrete with it. When erecting a temporary structure from lightweight materials, piles can be left unfilled, and then reused.

   

6. For horizontal stability, the piles are tied with a bar or channel. A channel is usually used for brick or foam concrete walls, a bar - for houses made of timber, logs or frame buildings. For tying with a beam, it is necessary to put a head on the piles, in which there are holes for fastening the beam. The channel is fixed by welding.

   

   The process of tying screw piles with timber for stability

The foundation of screw piles can be installed even in frozen ground, which is convenient for areas standing on floaters. Due to its high productivity and short lead times, this technology has become widespread, especially in the construction of houses from profiled timber or frame structures, for the popular Canadian technology. Buildings on piles can be installed on steep slopes and on the banks of water bodies, attaching piers. Also, gazebos, terraces, and other elements of landscape design are often installed on piles.

An important criterion for choosing the type of foundation for a house is the type of soil occurring on the territory. Building on clay often requires additional costs. One of the options for building a house on clay is to cut out all the bad soil and then fill the pit with compacted draining soil.

This procedure requires a lot of excavation and entails an increase in construction costs. To improve the reliability of the base on clay, it is necessary to provide additional measures.

Types of clay soils

Before deciding which type of foundation to choose, you need to know the type of underlying soils and their characteristics. For this, engineering and geological surveys are carried out with laboratory tests of soils. The geological report will describe which soils prevail in the construction area.

Sandy loam - soil with a clay content of 10 percent

The type of soil, its moisture content and the percentage of sand particles affect the choice of foundation. According to the regulatory literature, clay soil is divided into:

1. Clay. Here, its content in its pure form is more than 30%. This soil can be used under the base if it is homogeneous in composition and the freezing point of the earth is above the groundwater layer. It is characterized by high flowability and plasticity.
2. Loam. It is sand with clay impurities. Its content in the soil is not more than 30%. Loam is also subdivided into light, medium and heavy.
3. Sandy loam. Here the presence of clay does not exceed 10%. This type of soil is almost never used in construction, due to the high probability of its movement under the action of groundwater.

Depending on the origin and place of occurrence, glacial and alluvial clay is distinguished. Glacial soils are characterized by a high bearing capacity compared to other soils of this type. If the layer is large and deep, it can be used under the base. As the depth decreases, the plasticity of the clay increases.

The alluvial type of clay soil prevails in the lowlands, near water bodies. Due to its high ductility, its use in construction is very limited. Such soil can float, causing cracks in the building.

Choosing a foundation on clay

When choosing a foundation for a house, it is necessary to determine the soils that lie on the construction site, as well as several very important parameters:

1. Soil water content.
2. The percentage of clay particles.
3. Ground water level.
4. The depth at which the soil freezes.

To find out the water level in the soil on the site, you can look into the well or do engineering and geological surveys. Each region has its own depth of freezing of the earth, therefore, to determine this parameter, it is necessary to use the regulatory literature and select it from the tables given in it.

On the same clay soil, you can build different types of foundation. The main criterion for choosing a foundation is the material of the walls, the number of storeys of the building, the presence of a basement. For buildings with a heavy load (wall material brick and concrete) on any type of soil (sandy loam, loam, clay) and the presence of a basement, a deep strip foundation is used.

Base types

When the water level in the soil is below the freezing height of the soil, a monolithic strip foundation with an enlarged sole is used. The bearing area becomes larger, which allows you to evenly distribute the pressure. It is necessary to divert water from the tape bases by laying a sand cushion and drainage pipes.

Another option is a shallow strip foundation. This type of foundation is best used for light wooden houses. The soil should contain a minimum amount of clay particles and the groundwater level should be below the base. This type of foundation is tied into a rigid structure to distribute the impact of the soil along the entire length of the tape. With this option, there are large bending forces, so two reinforcing belts are arranged. The shallow strip foundation is a general floating system that is immune to minor disturbances from the soil. Watch the video on how to build a strip base on clay.

With a lot of pressure from the future home, the presence of heaving soils and low groundwater, choose a slab foundation. In most cases, it is expensive, but also the most sustainable. This type of foundation is a floating slab on which a large house can be built. It is possible to make a floating slab in the form of a concrete strip.

A floating foundation is well suited for building on clay. The load from the house is evenly distributed, and when the earth is blurred or shifted, the entire slab will move completely. The floating slab is not deep, but always on a sand and gravel cushion.

If groundwater is located close to the surface of the earth, then it is better to use a pile foundation on clay. Piles are driven or screwed to the depth of hard rock. The support of piles on dense rocks ensures the stability of the foundation, and hence the building as a whole. It is worth remembering that if the choice fell on this type of foundation, then the owner of the house will have to build a house without a basement.

To fix the piles, they are tied with a bar or channel. The timber is used for wooden houses, the walls of which are made of logs or timber. If the walls are brick or foam concrete, then a channel is used. A special head is put on the piles, and the timber is tied with the help of holes in it.

Not everyone decides to choose a floating columnar foundation for a building on clay. It can only be used for wooden houses. Instead of a monolithic structure, FBS blocks or masonry from wall blocks are used. Due to the small supporting surface of the log, the lower crowns of the log house are made of timber, reduce the pitch of the pillars, preventing the wood from collapsing. For this configuration, both a floating slab and a concrete strip are used. Watch the video on how to build a concrete slab on clay.

The construction of a house from foam blocks has become widespread. It can be attributed to light materials, with minimal pressure on the soil compared to brick or concrete. For houses made of foam blocks, the foundation is used shallow tape and pile.

Causes of foundation deformations and measures to prevent them

When building a house on clay, you should be aware of their features. Depending on the type of clay, the content of sand particles reaches a minimum of 5%. Under the action of groundwater, sand can be washed out, which will entail subsidence, heaving and plasticity.

The most common causes of damage to building foundations due to clay are:

1. House drawdown. When the sandy component is washed out by groundwater, cavities appear, which leads to subsidence of the house. This is typical with a high location of groundwater and high pressure on the base.
2. Heaving. It appears during the construction of the foundation above the freezing level of the soil, which contains loams or water-saturated clays. When freezing, water expands in size and acts on the base from below.
3. Effects on the foundation from the side. The more it is in depth, the higher is the load. Clay, due to its plasticity, acts on the base from the side, which entails the possibility of cracks or splits.

To take into account the impact of the earth from below, it is necessary to lay a reinforcing cage throughout the volume, which connects the top and bottom of the base.

For minimal lateral impact, the sole of the base is made wider than the upper. For waterproofing, it is advisable to cover the side with machine oil or tie the base with a film. With a decrease in the base area from the side, the action of forces during soil heaving decreases.

The depth of soil freezing can be changed down by insulating the soil with special materials around the building.

It is not always the case that the soil on the site is ideal for construction. Such as swampy, unsteady or heaving, they are not very suitable for building houses. But there is no need to despair, although on such soil it is laborious and financially expensive, it is still possible to build a house on such a site. In this situation, the so-called floating foundation can help you out.

What foundation on clay soil to choose for the house

Depending on what you are building, you can use one of 3 floating foundation options for your home.

So, what technology should be used?

Materials and tools needed to build a foundation for clay soils

• crushed stone;
• sand;
• boards;
• roofing felt or roofing felt;
• fittings;
• bayonet and shovel;
• concrete mixer;
• wheelbarrow;
• mesh for screening sand;
• building thread;
• nails and hammer (for formwork);
• level;
• rule;
• roulette;
• metal pin.

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Variant of a monolithic floating foundation of a house for clay soil

On clay soil, there is a high probability of breakage of the structure, subsidence and buckling of the soil.

This type of foundation is a reinforced concrete slab freely located on a base (pillow) of loose building materials.

This type of floating foundation is chosen for the construction of fairly heavy structures made of concrete blocks, stone or brick.

Other name - . It is made using a clean mortar without large stones, and gravel or crushed stone of medium and small size is suitable as a filler.

For the construction of such a foundation for a house, formwork is necessary. The most suitable equipment in the compaction process is a vibrator, which greatly improves the quality of concrete. This foundation does not require a large base thickness, 40 cm is enough.

Important: the shape and size must exactly match the parameters of the house.

So, where does the floating foundation begin? The technology of the device provides for the initial laying of the base (cushion) under the foundation.

For this, you need: soil, coarse sand, crushed stone or a mixture of them. The thickness of the base should be about 40 cm.

The pillow must be moistened and carefully tamped.

Then you need to make a panel formwork 30 cm high. Any flat boards that need to be fixed with a peg from the outside are suitable for its construction. The gap between them should not be more than 1.5 m.

Another important point is the filling of stiffeners. For their device, grooves are dug out and roofing felt or roofing material is laid on their bottom. This is necessary to retain moisture in the solution.

The floating slab foundation must be reinforced. Carry out this procedure after completion of the preliminary work. To do this, reinforcement is laid out throughout the base. Uniformity is the main requirement when performing work. Reinforcement is also laid along the ditches.

After that, you can start pouring the foundation with concrete. As reinforcing elements, you can use thick wire, metal rods, small pieces of iron pipes, a profile, etc.

A mixture for pouring a floating foundation is prepared from Portland cement M 400. It is mixed with crushed stone in a ratio of 1: 2. If coarse sand is used, the ratio will be 1:1:1. The strength of the foundation also depends on the quality of mixing.

After filling is completed, the surface of the slab is rammed and leveled with a level. If you need to level some areas, you need to add a solution.

It is advisable that someone help you at this stage of the work, it is much easier for two to carry out this procedure. Use the long rule in your work. You can make it yourself or purchase a ready-made version (aluminum).

The pouring of the foundation must be carried out at the same time. In case of any doubts, it is better to fill the entire area, but not entirely, but half. You can continue the next day. It is not recommended to fill the slab in parts.

When the pouring is completed, the surface of the finished slab is covered with any sheet material or film. 2 weeks in this state is enough. Moisten the foundation from time to time, then its curing will be correct and of better quality.

After hardening, the formwork is dismantled, and in its place a brick plinth is laid. As with the construction of other types of foundation, the plinth must be equipped with holes for ventilation.

In its absence, mold may appear. The size of the ventilation outlets is at least 15x15 cm, and their location should be at a distance of 15 cm above the ground.

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Strip foundation on clay soil

Strip foundation is used for lighter structures. Its base is shallow. is a closed reinforced concrete structure, for the device of which a pillow (base) of gravel and sand is required. Most of all, the strip foundation is suitable for a site that has a horizontal profile (differences of no more than 30 cm). Any of the soils listed below are suitable for its device. This:

• clay;
• loamy;
• sandy soil.

On such a foundation, only fairly light prefabricated and frame-type structures can be built.

The device begins with earthworks. After marking, you need to dig a trench around the entire perimeter of the future building. The depth of the trench is about 70 cm, the width is 50 cm. Crushed stone is poured into the bottom of the trench, its layer should be 30 cm. Then sand is laid, if it is dry, it will need to be moistened.

Please note that the crushed stone layer is mandatory as it acts as a shock absorber, preventing the possibility of local subsidence. The finished pillow must be moistened for 3 days. After watering, the base must be carefully tamped. When the pillow is ready, you can make formwork.

If there are differences in the area, the filling must be done in a stepwise manner. Like monolithic, strip foundation is also subject to reinforcement. For this, a special mesh or metal rods are used.

Reinforcement is carried out at 2 levels. 1st row - 5 cm from the bottom side of the concrete, 2nd row - 5 cm below the top edge of the foundation. As in the first case, the filling is carried out simultaneously.

A completely flooded foundation is covered with a film and moistened daily for a week. Then the formwork is removed and the laying of the basement begins.

The positive characteristics of a strip floating foundation include the following:

• erection under the force on their own, enough 2 workers;
• affordable cost;
• professional skills are not required;
• well suited for the construction of any light structures;
• it is steady on heaving soils and at intraground stresses.

Of course, like any foundation, the floating tape has its drawbacks:

• not recommended for the construction of heavy objects made of brick, stone, etc.;
• not suitable for areas with large differences.

The basis of any structure is the foundation, which determines the life of the construction object. The cost of arranging the foundation makes up a third of the total estimated costs and it is not advisable to save on it. Not always high-quality building materials guarantee durability. The surface on which the construction is carried out is of no small importance. The foundation on clay soil is fundamentally different from the pouring of the foundation in the chernozem regions.

Building a solid foundation on a heaving base is a serious task. After all, it can behave unpredictably, which is associated with the ability to retain moisture, push the building. Insidious clay is easily eroded by water, loses its integrity, and opens up moisture to the elements of the constructed building.

Before building on problematic soil, study its properties, decide on the type of construction. The cost of a mistake is high. These are cracks, failures and possible destruction of the building. The construction of a capital facility in the zone of clay soils requires the assistance of design organizations. If you plan to build an outbuilding, a bathhouse or a room for a vehicle, then you can cope with this task yourself by studying the recommendations indicated in the material of the article.

The main feature of clay is the ability to quickly erode under the influence of water, without passing it deep into

Preparatory activities

If there is no choice and you have to build a foundation on clay soil, pay special attention to the following points:

• the type of clay-containing soil, which is determined during survey work involving drilling, sampling at the future depth of the base. Perform geological exploration in the spring, when the groundwater level is maximum, which allows for detailed studies;
• the level of soil freezing for your area, which is determined for a particular region using reference information;
• moisture concentration. Moisture can be determined by leaving the sample to air dry. If the process takes several hours, then this indicates high humidity, causing swelling;
• depth of aquifers located in the upper layers of the soil. Having completed the drilling of the pit and, focusing on the well located nearby, you will assess the level of the location of the aquifers.

Let us dwell in detail on the types of clay soils.

Clay soils are called heaving, and before starting construction, it is strongly recommended to conduct studies of the composition and homogeneity of soils on the site

Varieties of clay soil

For clay soils, a characteristic feature of the structure is the presence of microscopic plates, in the gap between which moisture is concentrated and stored. This nuance causes the soil to tend to a significant increase in volume at a negative temperature, when frozen water swells up the array and gradually displaces the foundation of the building.

You can try to knead the soil with your hand. Of the loamy fractions, the “sausage” will crack, and the plastic mass indicates that you have clay in front of you, which is difficult for construction.

The soil is different in different regions. Before you make a foundation on clay soil, determine what kind of soil is on your site:

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If the type of soil at the future construction site is determined, the level of water layers is known, the depth of freezing is calculated, then you can choose the optimal foundation for further work. The foundation for the future construction, made on a clay base, must have high strength and counteract the reaction of the soil.

• tape, deepened to a shallow depth and representing a monolithic structure with an expanded sole. It is equipped with the location of aquifers of soil below the freezing point;

On clay soil, you can build absolutely any type of foundation.

• pile construction, effective with significant deepening of piles and close location of aquifers. The expansion of the lower part of the supports makes it difficult to push the foundation under the influence of swelling forces;
• combined strip-pile foundation, combining concrete supports and a strip shallow contour into a single frame. It is applied at a close arrangement of ground waters.

The technological features of the construction of these foundations, intended for clay problem areas, differ from those adopted for standard soil types, as they have a complicated design and require increased financial investments. Let's get acquainted with the process of their arrangement.

Preparation of the tape base

Foundations for buildings can be made on clay soil using a strip base. A foundation on clay soil with high humidity will be more expensive than a similar structure in a non-problematic area.

It is not difficult to create a strong tape base if you use the technology performed according to the proposed option:

• Mark the construction site in accordance with the requirements of the project documentation.
• Dig a trench along the perimeter of the contour, the size of which should be 3 times the width of the future foundation, and the depth should be the freezing point.

For the construction of country houses on sandy loam and loam, with deep groundwater, you can lay a strip foundation

• Make the base 25% wider than its top. This will reduce the reaction from the ground, increase the area of ​​\u200b\u200bsupport, prevent deformation or subsidence of the building.
• Assemble timber, slate, or metal formwork, depending on the material available at the construction site.
• Fill the bottom of the trench with gravel with a layer of at least 15 cm, tamp.
• Lay a layer of sand, re-compact the sand and gravel, which will compensate for the reaction of the soil, remove excess moisture from the base.
• Cover the surface of the bottom and walls with roofing felt or plastic film to waterproof the base.
• Mount the reinforced reinforcement frame in the cavity, using wire, fix its elements.
• Prepare the concrete mortar according to the recipe, pour it into the formwork to the required tape height.
• Remove air pockets using an armature or internal vibrator.
• Plan the concrete surface of the future foundation.
• After drying, cover the surface with a waterproofing coating of roofing material.

The deepening of a monolithic tape base one meter below the level of occurrence of aquifers in the ground will provide compensation for soil forces and form a stable foundation for any building. Despite many disadvantages, using the advantages of clay, which can withstand significant forces from the mass of the structure, it is possible to form a strong structure for the construction of the building.

The depth of the foundation on clay soil directly depends on the clay component, the level of freezing and the occurrence of groundwater

Column construction

A pile foundation on clay soil has its advantages. When installing piles, you can enter a solid layer that is not affected by temperature changes and groundwater. This type of foundation is effective for closely spaced groundwater. The extensions of the lower part of the supports will increase the stability of the structure, its resistance to buoyancy forces. As a columnar foundation can be used:

• reinforced concrete pillars driven in the form of special pile fields. Under the main walls, reinforced concrete supports are immersed in rows, under the supporting columns - in cluster groups, and individual pillars are mounted under individual racks. Grills laid on piles unite the structure into a monolithic base;
• bored piles are formed by pre-drilling holes of increased diameter with an interval of 2.5 meters. They are located at the corners of the building and under the main walls. The base is filled with sand gravel cushion, which is concreted with a 10-centimeter layer. Metal, polymer or asbestos-cement pipes are lowered into the cavity, which are reinforced and filled with concrete;
• Screw supports, which are based on durable steel pipes. They are easily twisted into the ground using simple mechanical devices.