In addition, there is a possibility of destruction or deformation of load-bearing columns and base brickwork. Also, foundations often lose their strength due to sudden changes in temperature of the external environment and soil, and therefore, over time, concrete collapses, and the metal of a columnar or strip foundation corrodes. To preserve the structure of metal and concrete, it is necessary to carry out special reinforcement of the foundation, which for each specific foundation has its own technology and specific implementation.

It is clear that any foundation will deteriorate over time; the main thing is to prevent that borderline moment when the foundation is completely destroyed or becomes unsuitable for use. It is possible, of course, to increase the service life of the foundation, but such technology is expensive and not every company can implement it correctly. We’ll talk about how to strengthen the foundation correctly and protect it from destruction in the article.

When there is an urgent need to strengthen the foundation

• There are visible results of corrosion due to the influence of ground and surface water;
• The columns are deformed, their location and orientation change, and an uneven slope of the slab is created;
• Concrete columns become deformed and cracks appear in them;
• The angle of inclination of the building changes, cracks appear in load-bearing walls and ceilings;
• The destruction of the wooden grillage began due to exposure to moisture and insects;
• The building tilts in any direction, which are not associated with natural soil movements (surveyors will immediately detect such a problem);
• An orientation displacement of the columns was detected, and the belt clips were displaced horizontally;
• There are breaks in the exterior of the concrete masonry or existing supports have visible defects.

There are many problems associated with deformation and destruction of foundations, when reinforcement needs to be done as quickly as possible. Otherwise, the situation may lead to the destruction of the building.

Main factors of foundation wear

• Natural. Seasonal soil movements, freezing through boundary temperatures, exposure to highly acidic or highly alkaline groundwater;
• Technogenic. Uneven load on the foundation, soil, water and air pollution, changes in soil structure. It is also worth noting that the construction of a building in a technogenic zone also negatively affects the foundation and contributes to its rapid destruction through the influence of physical, chemical and biochemical processes.

As a rule, each area has its own reasons for foundation subsidence, which can lead to the slow destruction of buildings.

First you need to get ahead of the cause of destruction, and then use technology to restore or strengthen the foundation, otherwise all the efforts and money invested will be wasted.

Situations in which it is worth strengthening

Strengthening foundations is necessary in the following cases:

• During soil deformation with shear. In such cases, reinforcement is carried out in order to neutralize the natural movement of the soil and the influence of groundwater. Often this situation arises during the restoration of architectural monuments that are installed on old soils, already washed away by water, or karst deposits;
• When constructing additional superstructures and attic floors that are not provided for in the development project;
• When increasing the load-bearing concrete jacket by deepening the basement;
• If powerful mechanized construction begins in neighboring areas.

Before starting work, you need to study the conditions of the foundation in detail in order to determine the key problems and ways to eliminate them. If you need to find out what condition the foundation is in, deep punctures are made, right down to the base of the foundation.

Injection method.

Then, based on the data obtained, restoration drawings are made, samples of the soil, concrete jacket of the base and waterproofing of the underground part are taken to determine the causes of the deformation. It is also recommended to take samples of the sole, but doing such procedures yourself without special equipment and a drilling rig is not recommended.

How to calculate base reinforcement

First, you should determine the reason for the deformation of the base. There are many reasons, but they all need to be taken into account. Accordingly, the loads that are transmitted from the ground to the underground part of the structure are first collected. Of course, it would be nice to have construction drawings of the foundation on hand, but for old buildings it is almost impossible to find such documentation.

The collection of loads is done using measurements of the base itself, then the permissible loads from the structure of the building itself are calculated.

If it is necessary to strengthen the foundations of old buildings, then geodetic surveys of previous years are not taken into account due to the expiration of the statute of limitations.

But laboratory studies of the state of the foundation can provide more complete information, because then not only structural, but also molecular analysis of the composition of the foundation is carried out. But, again, it is practically impossible to carry out such analyzes with your own hands.

Why does foundation deformation occur?

1. Low quality building materials;
2. The wood of the grillages decomposed, mineral acids formed, which destroyed the cement;
3. There is no masonry mortar or it was used in minimal quantities;
4. Cracks appeared in the base;
5. Uneven placement of concrete blocks, especially in precast concrete foundations.

Strengthening external foundations.

Strengthening the foundation of a private house

• Weathering protection. Such protection is done on industrial and administrative buildings when weathering of building materials from the base occurs. Weathering occurs in brick and rubble masonry of the strip or column type, because They are characterized by low strength and water resistance. First, the outer surface of the base is leveled using a metal mesh, then problem areas are carefully tightened with cement mortar. In the case when the foundation is weathered over the entire area, the entire surface is plastered, additionally waterproofing materials and polystyrene are used for additional thermal insulation of the surface.
• Deformation of the base. It occurs through the influence of aggressive groundwater, and therefore it cannot be done without cementing. The visual result of groundwater exposure can be seen by excavating the foundation. For cementing, a strong load-bearing grillage is made, preferably made of steel or oak. Then several main wells are created into which concrete is poured. If concrete is supplied under pressure, then it squeezes out the light fractions from the concrete base and replaces them. After a few days, the new concrete hardens and crystallizes along with the old concrete.
• Strengthening reinforced concrete pillars. Reinforced concrete pillars can become deformed due to improper installation and pouring technology. After all, the pillars inside are filled with concrete and protected by reinforcement. But the reinforcement of the pillars has to be done only from the outside, because load-bearing structures are filled with concrete. Therefore, to strengthen reinforced concrete foundations, external reinforcement is done along pillars at a height of at least 20 cm from the soil level, all sections of rods are connected to each other. You can also connect the pole rods under the floor of the building if the structure is pinned.
• Install additional piles and use them to raise and secure the concrete foundation. It is not difficult to carry out such work, but here you need to use detailed geodetic and construction calculations, because the piles are made of concrete and have a large mass. There is a whole technology for installing piles. At the moment, it is considered the most progressive and optimal for strengthening almost all types of foundations.

Installation of piles

This is a progressive and reliable way to strengthen any type of foundation. It is based on the technology of eliminating the impact of soil directly on the base itself and transferring the entire mass to built-in piles. If sufficiently dense soil is found during soil analysis, then the installation of piles is considered optimal.

You should not think that concrete piles are ordinary piles with filling. They differ in structure, filling; a special drilling rig and drilling injection piles are used. The peculiarity of the technology is that it is possible to strengthen the foundation of a private house even in hard-to-reach places, and the quality of the work will not suffer from this.

The old foundation is relocated on vertical piles: a – with transverse distribution beams; b – with longitudinal ones; c – section according to 1-I; 1 – foundation; 2 – wall, 3 – piles, 4 – transverse beam; 5 – longitudinal beam in the groove.

Bored piles - features of use

The key disadvantage of the technology is the limitation of the installation location of the structure. When installing bored piles, long transverse beams are used, which are fed at a specific angle under the foundation. This angle is calculated by surveyors.

Drilling holes is accompanied by shaking of the soil, and therefore it is prohibited to do it yourself, because in such cases the release of loose soil is possible. And this is additional shrinkage of the soil, which should not be allowed.

Vertical boreholes are more practical, but are significantly more expensive. They are installed along the base, connected by a special reinforced concrete beam and additionally reinforced. When installing several of these piles at once, it is recommended to use reinforcement in pairs in order to ensure a more durable structure, especially when exposed to soft soils. This technology cannot be used to strengthen load-bearing columns.

Strengthening the foundation of a building using bored piles: 1 – bored piles; 2 – anchors; 3 – beam; 4 - foundation of the building; 5 – cast-in-place sealing of the beam.

This technology is popular, but does not always pay off. After all, it is prohibited to use it in old cities where there are ancient buildings, architectural complexes and other cultural heritage structures.

Damage to facades and foundations due to vibration and displacement due to drill pillars will lead to their deformation and destruction. Therefore, bored piles are more common in industrial areas, as well as in young cities with reinforced concrete foundations of pile or monolithic construction, but not brick or stone.

How to strengthen a foundation using press-in piles

This option of strengthening the load-bearing structures of buildings is more practical in conditions of dense development with old buildings. They are installed closer to the wall and directly near the foundation. Technology for installing pressed piles:

• Strengthening the base and load-bearing walls with concrete pipes, wooden formwork or scaffolding.
• Installation of metal pipes, which are pressed into the ground with a pneumatic jack and welded together;
• Backfilling of soil at the site where the piles are installed.

To connect supports of any type to the foundation, you need to use various metal structures that are welded to the foundation reinforcement or connected to concrete with anchors. Special reinforced concrete clips are excellent for such purposes. The length of the piles is selected strictly according to the type of soil, and the end of the structure should rest against a dense ball of soil.

The diameter of the piles is calculated individually for each building and depends on the type and thickness of the supporting foundation. But, before strengthening the foundation using this technology, it is worth first conducting a detailed study of the soil, because, due to excessive vibration, deformation of the columns, supports and masonry foundations of neighboring buildings is possible.

Injection fastening of the foundation for masonry and columns

Here, drilled injection piles are used, which differ from pneumatic supports in the design and method of supplying the solution. Strengthening the foundation is done as follows: a concrete solution is pumped under pressure into such supports, which then creates a so-called monolithic cushion under the foundation of the masonry itself.

This solution is considered optimal for deformation of brick and rubble masonry, because a uniform concrete plane is created that can withstand enormous loads.

When concrete is pumped, the soil is compacted, a monolithic slab is created, drilling is carried out using various methods, soil movement is practically not felt, so the method sometimes helps to save architectural monuments, where the masonry itself is a work of architectural art. But this method costs a lot of capital investment, because complex drilling equipment is used, detailed geodetic studies and calculations are carried out, and architects and drilling specialists are also involved.

Making a monolithic slab yourself is almost impossible from a technical point of view. It is also worth using the method to strengthen individual supports, because then the distribution of the mass of the structure will be normalized, and the concrete masonry will withstand additional loads.

How to strengthen the foundation should only be decided by specialists, and not by the home owner. But the methods of reinforcement will be the same, whether it is a strip base or a columnar base with columns.

Time passes, and the foundation of the building begins to slowly collapse. Almost every owner of an individual cottage or house faces this problem. How to strengthen such a foundation, how to increase its reliability?
Today, strengthening the foundation of a private house with your own hands can be done in several ways. But before doing such work, it is necessary to find out the reason for the destruction of the old foundation and choose a technique that partially strengthens the foundation under the house.

Reasons for strengthening the base

Strengthening the foundation with your own hands is required only when the following serious reasons arise:

• Weight of the building. The foundation of a brick house begins to collapse due to the heavy weight.
• The calculations were performed incorrectly.
• Extensions and additional buildings had a negative impact on the overall condition of the entire structure.
• The condition of the soil has changed.
• Seismic impact.
• The house was redeveloped without taking into account the additional load on the foundation. It was not taken into account during the design.
• Improper operation of the entire building. For example, a drain for wastewater was not made, and the house began to be washed away.
• Strong soil vibration from blasting at a quarry or nearby highway.

Ancient buildings always had a strip foundation. It had negative performance properties. Strengthening the foundation of a wooden house standing on such a strip foundation can be done using an additional reinforced belt.
You can strengthen the foundation of an old house by replacing the old foundation. It is enough to raise the house on jacks and strengthen the old foundation with an additional reinforced and concrete layer.
It is impossible to strengthen the foundation of a private house made of bricks in a simple way, like “we’ll install the formwork and then fill everything with concrete.” This option won't help.
The depth of damage to the foundation of the house will itself tell you what strengthening method needs to be applied so that the first and second floors of an individual cottage can stand for many years to come.

Strengthening technique

We already understand how to strengthen the foundation of an old house. You can replace the supports of the columnar foundation, increase the thickness of the old foundation, or completely replace it.

Almost every owner knows well how to strengthen the foundation of a wooden, dilapidated house. But if the house is made of stone, many additional questions and problems arise.
To tie such a heavy house with metal fittings will require a lot of time and additional financial investments. To strengthen the foundation of an old house with your own hands, you need a completely different technology.
Most stone buildings stand on a strip foundation. How to strengthen a strip foundation, what needs to be done for this?

Shallow layer between the house and the soil

This foundation is directly dependent on the soil and all kinds of heaving phenomena. Lifting forces begin to put pressure on the base slab of the house, and it begins to tilt. As a result, cracks appear on the surface and the base begins to collapse.
To bring the lifting forces into full equilibrium, you need to constantly increase the area occupied by the sole.

Strip deep-buried foundation

On such a base, the sole of which is located below the freezing level, lifting forces do not have any effect. But if this happens, the best reinforcing method is to increase the area of ​​the sole.
Sometimes such a foundation begins to be washed away by groundwater. Their actions are so strong that the soil literally “leaves” from under the foundation slab. Reinforced concrete monolith becomes less durable due to high humidity.
To save the foundation, it is urgent to install a drainage system.
When the buried foundation begins to crumble, it is necessary to remove the damaged layers to strengthen it. Fill the exposed surface with cement laitance and then hydrolyze it.
If the base tape of the house is severely damaged, it needs to be built up with special reinforcing elements, for example, reinforced mesh. This is how you will strengthen the foundation in a private house.

Additional methods of strengthening

Today, new technological processes have been developed to strengthen the supporting structure under the house. Some of them will be discussed.

Shotcrete

This method of strengthening the foundation for a house is used for strip foundations when only the load-bearing foundation is damaged. It is only necessary to carry out restoration work concerning the outer layer.
With the help of shotcrete, the base of the house is strengthened and its water resistance is increased. When this technique is used, there is no need to install formwork, and the consumption of concrete mixture is noticeably reduced.
Before you start shotcrete, you need to do some preparatory work. A trench is dug around the entire base of the house, with a maximum width of two meters. The base must first be cleaned of debris and dirt.
Notches are made on the base of the house to increase the adhesion force of the concrete to the base.
To strengthen the restoration layer and make it more durable, a reinforcing mesh is laid on the surface of the base for the building. Then everything is poured with concrete.

Sole extension

Such strengthening of the foundation of brick private houses is used very often. It is used in case of deep damage, and when there is no need to use special equipment. All work is easy to do yourself.
How to perform this procedure correctly? A layer of soil is removed from the left and right sides of the base of the building. On the outside, as well as on the inside, additional prefabricated ebbs are installed. They are tied at the bottom with through anchors.
Concrete solution is poured into the resulting free space. The solution separates the base from additional flashings. At the top, flashings can be attached to the foundation using rebar. The free gap is filled with soil. Its surface is well compacted.
The main difference between this method for expanding the foundation of a house and installing formwork is the use and installation of ebbs made from a special, moisture-resistant material, as well as the installation of additional screeds.

Installation of an additional protective brick wall

This method can be done without the help of professionals. All work is done by hand.
Similar to the previous option, a trench is dug, no more than one meter deep. The surface is cleared of debris.
Structural defects are filled with cement mortar. The top is covered with any waterproofing material. Usually rolled roofing felt is used. A brick jacket is created on the surface of the roofing felt. When all the preparatory work is completed, the ditch is filled with very rich clay.

Reinforced concrete jacket

The columnar foundation is subjected to such reinforcement. Near each reinforced support, but first a reinforcing mesh is installed. Wooden formwork is attached to it. The free space between the formwork and the base is filled with concrete mortar. Such a structure reconstructs the base and also helps to increase the load-bearing load on the pillars.

Pile technology

This technique has become popular when repairing the foundation of a brick house or any wooden structure. The only exceptions are dilapidated wooden houses with completely rotten lower crowns.
The technology of this method has two varieties. The use of the first is possible in cases where the base of the house has minor damage.
Holes are drilled through the supporting structural part until the drill touches the ground surface. Reinforcing rods are inserted into the drilled holes. Concrete is poured into the resulting gaps in small parts. To implement this method, you will need special equipment, as well as metal and concrete rods.

The second method, the so-called “pile-screw” method, is used to replace the entire foundation or strengthen it. This is especially true when a village house has a shallow foundation installed on a rubble foundation.
First, holes are drilled, the depth of which exceeds the freezing depth of the soil. Tubular supports are taken, treated with an anti-corrosion compound, and then installed in prepared pits.
This method gets its name “screw” from the design of the piles. Special screw blades are installed at their ends. When the installation of the piles is completed, the upper parts are cut off and the size is set to the building level. For a small wooden house, it is enough to install one pile at the four corners of the building. Unfortunately, the pile method is only available to a specialized team; this method of strengthening the foundation is very difficult to carry out independently.
If you know the reasons that caused the destruction of the foundation, you can choose the right repair method. This will help to completely eliminate all defects and minimize the negative impact of all causes on the existing foundation. Now you know in what ways you can strengthen the foundation and how to do it correctly.

A wooden house is beautiful, warm and environmentally friendly. But, unfortunately, it is short-lived. The causes of destruction are different. Let's dwell on how to strengthen the foundation of an old wooden house with your own hands. The reasons for foundation damage are different: shifting soil layers, the operation of heavy equipment close to the house, incorrect initial construction. Whatever the reasons, one thing is clear - the foundation must be restored.

Causes and types of foundation destruction

When starting to strengthen the foundation of an old wooden house with your own hands, you first need to correctly determine the cause of its deformation.

There can be several factors for the occurrence of destruction:

• Due to changes in load, soil properties may change. Such changes are caused by soil erosion and high groundwater levels. If new buildings appear near the house, this can also lead to certain changes. The buildings seem to squeeze out the soil and thereby violate its density. The consequence of all this is the subsidence of the house or its warping.
• Poor quality initial foundation construction. When laying the foundation, the work may have been performed poorly, errors were made in calculating the depth of soil freezing or in choosing the grade of concrete.

Determining the cause of structural deformation is only the initial stage. The next stage is determining the extent of destruction. They are divided into four types:

• Minimal damage is visible defects. These include slightly peeling plaster. This damage is repaired very quickly.
• Average damage. These include different types of cracks. To eliminate defects, their nature should be investigated. Horizontal cracks are not particularly dangerous. Defects of a vertical or zigzag nature deserve more serious consideration.

Cracks usually occur due to subsidence of the foundation. Therefore, it is important to determine whether this process is progressing or is temporary.

Technologies for strengthening the foundation of an old wooden house

Depending on the degree of destruction of the foundation of the old house, certain work is carried out to strengthen it. The simplest and easiest to do with your own hands is to seal cracks, which usually occur when the house subsides slightly. To do this, you need to slightly widen the crack and clean it of dirt. Then prime it well and seal it with sand-cement mortar. Also, partial repairs to the support of the house can be performed if the building has sunk into the ground.

To do this, the structure rises. To perform this procedure, first of all we reduce the load on the base. It is necessary to remove all furniture from the house, dismantle the floor and remove the stove if it does not have its own foundation. If the house is small and light, then you can lift it with the help of a wagon. To do this, a wooden beam with a cross-section of 80×80 mm is placed at the corner of the building. Then they use the wagons as a lever, focusing on the log, and raise the house.

Heavier houses are lifted using a jack, which is placed in certain places. After the building has been raised to the desired height, the old foundation of the house should be built up using brick or concrete. For more serious foundation deformations, one side of the foundation is usually strengthened or, if necessary, the entire perimeter. Let's consider several types of strengthening the supporting structure.

Repairing the foundation by strengthening the corners

Sometimes, to strengthen the supporting structure of a wooden house, they limit themselves to strengthening the corners.

In order to do this work correctly, you must first expose the corners of the base. To do this, a hole is dug near each corner of the house, the diameter of which is about a meter. The depth of the hole should be half a meter lower than the depth of the old foundation. Reinforcement is carried out using a reinforcing lattice. The cell dimensions are 20x20 cm.

On the old foundation, the reinforcement is cleared of concrete in some places, to which a reinforcing lattice is attached. In this case, the connection should be made by welding. After the grate is installed, they begin pouring concrete layer by layer and leave it to harden. In order to increase the degree of reinforcement, you can strengthen not only the corners. In some places, ditches up to half a meter wide are prepared along the perimeter of the dwelling every one and a half or two meters.

The depth of the ditches is equal to the depth of the old support. Then reinforcing bars are attached to the steel rods of the old base and filled with concrete again. Thus, reinforcement occurs both in the corners and around the entire perimeter. This is easy to do with your own hands and significantly increases the bearing capacity of the foundation.

Concrete must be poured gradually in layers. This can be achieved by filling the recesses one at a time.

Strengthening the base with an armored belt

A frequently used and reliable way to strengthen a foundation with your own hands is to install a monolithic reinforcing belt around the old base. Watch the video on how to strengthen the base with an armored belt.

To construct it, a certain algorithm is used:

• Prepare a trench around the house. It must be such that there is free access to the base and the possibility of unhindered work. Its width can be 50–60 cm. The depth should be at least 0.6 meters below the old support.
• For better adhesion of the old base and the reinforcing belt, the foundation walls are thoroughly cleaned of foreign objects. It should be cleaned thoroughly; it is best to use a metal brush. Next, deep priming is carried out.
• A sand and gravel cushion is poured onto the bottom of the trench, which is well poured and compacted. It should be fairly well compacted.
• The formwork is assembled from boards or plywood.
• We prepare holes in the old base with a diameter larger than the cross-section of the reinforcing bars by one millimeter. It is best to use reinforcement with a diametrical cross-section of 12 mm or 14 mm. We install steel rods by driving them into the prepared holes. The distance between them should be 25–30 cm. It is better to arrange the rods in several rows.
• A new reinforcing belt or reinforcing mesh is attached to the clogged rods.
• Start pouring concrete layer by layer. The thickness of the layers should not exceed 20 cm.
• Waterproof the reinforcing belt and arrange a blind area.

Strengthening the supporting structure in this way allows you to evenly distribute the load over a double area.

Strengthening the foundation by installing piles

The foundation of an old wooden house can be strengthened using piles, and there are several ways to do such work yourself:

• Bored method. On both sides of the base, wells about two meters deep are drilled every one and a half meters. Then we reinforce and waterproof the recesses. After all preparatory work has been completed, the wells are filled with concrete.
• Using screw piles. This is a less labor-intensive method. True, in order to perform it correctly, several people will be required. It is necessary to simultaneously monitor the position of the rods and directly carry out work to deepen them.

After the piles are installed, they are attached to the house using anchor bolts.

Cracks on the walls, destruction of the base, subsidence of the corners of the house, bulging and curvature of the walls, both vertically and horizontally, subsidence of the floor, violation of the integrity of the finish - all this indicates the beginning of the process of destruction of the foundation structure. And here the question arises of how to strengthen the foundation to prevent these deformations. Several factors influence his decision.

For the beginning of deformations of a private house that has been in operation for several years, it is first necessary to determine the percentage of physical wear and tear according to VSN 53-86. This will show the category of technical condition of the foundation, and in case of emergency status, it would be more advisable to completely replace it.

It is possible that strengthening the foundation of a private house is associated with an increase in the load on it, such as adding another floor or attic; however, to choose the optimal method of strengthening it is necessary to evaluate the foundation itself, as well as the conditions in which it operates:

1. Engineering-geological conditions are a fundamental factor. Because some methods may simply be useless;
2. Loads acting on the foundation. Sometimes, even under heavy loads and bending moments, only strengthening the base (soil) itself is sufficient;
3. Dimensions of the existing foundation structure. So, for example, at a high height with a high reinforcement coefficient, it is very difficult to reinforce with drilled injection piles.

After assessing the above parameters, you can choose the best method for strengthening the foundation.

Amplification methods

With all the variety of methods, which vary depending on the structural type of the foundation structure and material, we can combine and highlight those that are most suitable for solving the problem of how to strengthen the foundation of a private house that has a strip or columnar structure.

However, if an increase in loads is planned or if deformations of a private house are caused by:

• Uneven settlement of the foundation structure;
• The presence of aggressive groundwater;
• Flooding of the area under the house.

Then, first of all, you should strengthen the foundation, after which you may not even need to strengthen the foundation itself. There are 3 types of soil consolidation:

Soil strengthening

Chemical

The most diverse in the number of methods used:

• Silication. The essence of this method is liquid glass, which, depending on the type of soil, is either mixed with two or three ingredients and then this mixture is injected into the soil - one-solution technology, or an undiluted solution of sodium silicate is injected into the soil, and then calcium chloride is injected - two-solution technology . Silication is used for loess and fine-grained soils with a high content of sand particles and having a water permeability of up to 5 m/day.
• Electrosilicatization. It is a combination of silicization and electric current, which is used for fine sands and sandy loams, with a water permeability of 200 mm/day, which are watered.
• Gas silicification. Combines silicification and carbon dioxide as a hardener. It is used for sandy and loess soils with a water permeability of 100-200 mm/day.
• Ammoniation. This method is based on the use of ammonia gas, which is injected into the soil under medium pressure. Used for loess soils to prevent their subsidence.
• Smolization. In this method, solutions of synthetic resins are introduced into the soil. Effective for soils with water permeability of 500-5000 mm/day.

The injectors are placed in different directions. Their location diagram is shown in the photo.

Thermal

The essence of this method is the combustion of liquid or gaseous fuel in drilled wells closed with valves. Firing is applicable to subsidence and clay soils.

Physico-chemical

This includes:

Strengthening the foundation

Cementation

This method allows you to strengthen the foundation in a private house made of rubble stone, rubble concrete or iron ore. Used to restore the strength of masonry under the following conditions:

• Deformation changes are weakly expressed, but are characterized by the beginning of the process of delamination of the masonry or partially collapsed stones;
• The base has sufficient load-bearing capacity;
• The increase in load is not provided or it is insignificant.

Technology: Injection pipes are installed into the reinforced structure in a checkerboard pattern, with a pitch of 500 - 1000 mm. Cement mortar is pumped through these tubes under a pressure of 6-7 atmospheres. The amplification is shown schematically in the photo.

Reinforcement with clips

The simplest and most reliable method of amplification. The clips tightly compress the reinforced structural element as the concrete gains strength, thus ensuring the integrity and solidity of the structure, and also forcing it to work as a single whole. Moreover, this method is applicable to foundations made both of stones or monolithic concrete, and of prefabricated elements.

Divided into 2 types:

Without sole widening foundation. This is how the foundations are strengthened:

• with a high degree of destruction of the material;
• without increasing loads;
• with a durable load-bearing layer under the base.

Technology: The site is divided into sections of 2 - 2.5 m each with a distance between them of at least 6 m. Trenches are developed on both sides of the existing foundation. The formwork is installed, reinforced with spatial frames and concreted. After the concrete has gained 70% strength, the adjacent area can be strengthened.

Important! The thickness of the clips is determined by calculation, but not less than 150 mm. And the spatial frames reinforcing the reinforced concrete cages should be assembled from closed clamps with a diameter of 12 - 14 mm.

With widening. This method can be enhanced under the following conditions:

• the foundation has a high degree of destruction;
• it is necessary to increase the load;
• there are stable soils at the base.

To what values ​​​​it is necessary to increase the dimensions of the sole can be obtained by calculation using the formulas of section 5. However, the new sections are a small part of the reinforced structure, so the base of the old element will still absorb most of the loads. This is acceptable with a slight increase, since the new part of the foundation will prevent the soil from being squeezed out to the sides. However, if significant loads are planned, then the widened part should be used through preliminary compression of the base.

Technology: Work is usually carried out using 1.5 - 2 m long claws. They dig holes along the foundation, the soil in which is compacted into 2 - 3 layers of crushed stone. Grooves are applied to the old structure. Install metal pins. Then the formwork is installed and concreting is carried out. After the concrete has gained strength, the soil is backfilled in layers and then compacted.

Advice! In the outer layer of a concrete or reinforced concrete foundation that has been in operation for a long time, modifications begin to occur that affect the achievement of solidity of the structure. To prevent this, it is recommended to remove the old layer of concrete, then clean and moisten the surface. Next, a concrete mixture is placed on it, which is thoroughly compacted.

Leading and deepening

Also refers to a method of widening the foundation, but this happens due to the use of various structural elements that are brought under the foundation and due to which it deepens. It is used when weak soils lie under the house at its base and it is necessary to transfer the load to a more durable layer of soil located at a shallow depth. In this case, the foundation is characterized by a weak degree of destruction.

Technology: Strengthening the foundation is carried out in sections 1 - 2 m long. Within the boundaries of the area, the soil under the foundation is excavated. Then a slab or other reinforced concrete elements are placed. Next, the soil is compressed using hydraulic jacks, and the gap between the old structure and the new connected element is filled with concrete, which is compacted with vibrators.

A method that does not involve excavation. It is used when there is a collapse of the soil on the site and an average degree of destruction of the foundation, leading to settlement of the corner of the house and bulging of the walls. It is also advisable to use this method if you plan to significantly increase the load, but the base has weak soils.

The essence of the method lies in the construction of root-like outgrowths, which transfer the load to more stable layers of soil.

Technology: Places for piles are marked. Wells are drilled using drilling rigs that can rotate and break through the thickness of walls and foundations. Next, reinforcement cages with clamps and injection tubes are inserted into them, through which the solution is injected. After cementing the wells is completed, the injectors are removed and the wellhead is pressurized with compressed air.

In many cases, this method is the most rational, and sometimes even more economical than other methods.

Reinforcement with bored piles

This reinforcement is most widely used in difficult construction conditions, however, under the same application criteria that apply to drilled injection piles.

Technology: First (stage 1), trenches with fastenings are developed along the strip foundation structure or around the columnar one. A groove is punched along the lower part of the wall, and a metal beam wrapped with wire is placed in it on the mortar. Then (stage 2) wells are drilled into which reinforcement cages are installed, followed by concreting. After this (stage 3), holes are punched through the existing foundation, and metal beams are installed in them in the longitudinal direction. Next (stage 4), the piles are pressed into the ground using jacks, and the beams are jammed. The last stage is the installation of formwork and concreting of the grillage, and after gaining strength, backfilling is carried out with layer-by-layer compaction. For greater clarity, how to strengthen the foundation using bored piles, you can refer to the photo:

Diagram of the stages of strengthening the foundation with bored piles.

Advice! It is advisable to consider several methods of amplification at the same time. This will allow you to choose the most rational method that satisfies both the engineering and technical side and the economic side.

Many residents of private houses sooner or later face such a problem as. This occurs due to shrinkage of the house and fatigue of materials. If the foundation has served for more than 10-15 years and has already exhausted its resources, then it’s time to update and strengthen it on your own. It’s very good if you built the base of the house with your own hands and know how everything was done, what frame structures were inside and what materials were used.

You can strengthen the old foundation by making a reinforcement cage, which is installed in the corners, or even better, along the entire perimeter, and filled with concrete.

Having noticed that the window openings are skewed and deep cracks have appeared in the foundation of the house, you need to begin strengthening the fundamental part of the structure. To do this, you can invite specialists, or you can solve the problem yourself. You should first analyze the condition of the foundation of your house in order to understand which method of strengthening the base will be the most effective and optimal in your specific situation.

Reasons for the destruction of the building foundation

Virtually anything can cause the destruction of the foundation of a house, from damage to materials to the presence of a building in close proximity to your home. Here are the main conditions that may occur:

Scheme of foundation destruction: (forces: a - gravity, b - soil resistance, c - frost heaving): 1. Soil subsidence; 2. Pushing out the foundation; 3. Frost heaving; 4. Foundation overturning.

1. Failure to comply with the technology of the house construction process during its construction, as well as the use of low-quality materials, which leads to rapid wear of the foundation.
2. The construction of the house took place without taking into account the characteristics and composition of the soil, which led to the incorrect selection of construction technology and the choice of the wrong materials.
3. Possible errors when calculating the load on the foundation when laying it.
4. Changes in groundwater levels, namely an increase, including abundant soil moisture (for example, spring floods).
5. Heterogeneous soil composition and soil movement can also lead to the need to strengthen the foundation.
6. Carrying out land or construction work in the immediate vicinity of the house, for example, laying pipes, building another house.
7. Possible freezing of clay soil, which is very common if the foundation was laid with errors, using a technology that was never followed.
8. A thorough redevelopment of a house, which involves the displacement or transfer (destruction) of load-bearing walls.

Before that, it is necessary to understand the reasons for its shrinkage and be sure to eliminate them. If you don't do this, the same thing can happen to the new foundation as to the old one.

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Where do you need to start?

The best place to start is by determining how you are going to strengthen the foundation of your home. There are three main methods of strengthening the foundation:

1. Classic way.
2. Reinforced concrete jacket.
3. Method of strengthening with piles.

All of them are often used in construction work, each has its own pros and cons, as well as “indications”. You should choose one method or another based on your own preferences and financial capabilities. To begin, gather all the tools and materials that may be useful to you to strengthen the foundation. Here is a list of such tools:

1. Bulgarian.
2. Welding machine.
3. Construction tape.
4. Special cutters for fittings.
5. Construction hammer.
6. Reinforcing cages or rods.
7. Piles to strengthen the foundation.
8. Concrete mixture.
9. Crushed stone.
10. Construction gloves.
11. Shovel.
12. Wooden beams.
13. Waterproofing material.

Having prepared everything you need, you can get down to business. Next, we will consider all three methods of how to strengthen the foundation in order to understand the features of each of them.

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Strengthening using the classical method

This is one of the most economical methods, which has already been tested for centuries, and therefore you can be 100% sure that such a foundation will last for many years. To implement this type of work, you will not need new materials and technological tools; what you have already provided and prepared will be enough. The essence of the work is to create a new one around it, thereby strengthening it and making it more durable and protected. To begin with, it should be done from all corners of the house to give them rigidity. The new layer of the foundation of the house must be at least 1 m wide and half a meter lower in depth than the old layer.

Now you can, armed with the necessary tools, make a reinforcement cage for corner joints. After making them, lower them into the prepared holes and fill them with high-quality and durable concrete. At this stage, you should not save on cement mortar, because it should serve you for many years. The work must be carried out very quickly so that the bare areas do not remain so for too long. If work will be carried out along the entire perimeter of the house, then each section must be done in stages. It is not recommended to proceed to the next until one segment has dried.

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Reinforced concrete jacket as a way to strengthen the foundation

This type of work assumes that not only the old foundation will be strengthened, but also the walls of your house. To do this, special anchors are built into the walls and foundation into which concrete is poured. Before strengthening the foundation, you need to waterproof the prepared foundation using special means. The next step is to build a wall made of brick, which is the most reliable material in this situation. Strengthening the foundation using this method is the best way to secure your home.

Along with this, they also use the method of widening the foundation, which involves adding it from all sides. First, you need to measure and mark everything on the grip, after which you can tear off the old foundation one by one through the grip itself. The surface must be cleared of construction and other debris, after which, in the place where the old foundation is located, or rather around it, dig a trench and fill it with crushed stone. Now you can drill holes in the base into which the metal pins will be installed. The next step is to install beams between the brick wall and the base.

This method of strengthening the foundation of the house should bring very good results. Even significant damage to the foundation can be corrected by strengthening the base using this method. After carrying out all the above work, it is necessary to install the formwork in the trench and fill it with concrete. This way you will get a completely strengthened foundation of your house, including even the walls, which will provide even greater protection from destruction.

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Strengthening a house with piles

Another method that simply cannot be ignored, because it is used in cases where the foundation is very badly damaged and its strengthening is an urgent need.

If there are problems with the soil, for example, its shrinkage or rising groundwater levels, then it is best to strengthen the foundation of the building by installing special piles.

The work is quite complex and requires attention, but the results are very good. Piles can be installed around the perimeter of the old foundation, or under it. Here it is necessary to find an individual solution by exploring different ways to strengthen the base of the house.

There are several ways to strengthen houses with piles:

1. The drilled method, the essence of which consists in punching wells along the entire perimeter of the building, inside and outside. They are stuffed with reinforcement and filled with concrete. The depth of each well must be at least two meters, and the distance between them must be maintained at 1.5 m. These piles are attached to the house using reliable anchor bolts.
2. The pressing method is used in cases where the houses are already quite old and it is impossible to apply excessive physical force and pressure to them. In this case, the piles are not driven into the foundation, but are slowly and gradually pressed in. This is done using special equipment, since it is simply impossible to carry out this type of work independently.
3. Screw method. This is the most common method used when you need to strengthen the foundation, and it is the most effective. In order to install the piles, you will need outside help, since a pair of workers is not enough.

There are some nuances that you need to familiarize yourself with before you decide to strengthen the foundation of a private house in this way:

1. First, you need to carefully study the old foundation, since the choice of one or another method of installing piles depends on its condition. If the base is very old and can collapse at any time, then it is better to choose the method.
2. Many people are interested in whether it is possible to do such work on their own, the answer is obvious: in most cases you will need special equipment that is created specifically for such purposes. Of course, you can do all the accompanying work yourself.
3. Most often, screw piles are used to strengthen the foundation of houses. This is a convenient and effective method that requires the participation of special equipment and tools.
4. If you need to strengthen a strip-type foundation, then it is better to start by balancing the influence of underground forces. This is done by increasing the base area of ​​the house.