Minimum distance between screw piles. How to determine the distance between screw piles At what distance to place the piles

Foundations on piles have been known for a very long time. For the first time, piles began to be used in the construction of bridges, where reliability and quality were certainly required.

In this article we will look at what distance should be between screw piles in a frame frame.

In ancient Rus', churches were often built on wooden piles. The foundation on piles is used for heaving and embankment areas, with an extremely unreliable composition of the upper soil, which contains clay, is highly saturated with water, humus, peat, etc. It is used on various surfaces without worrying that uneven shrinkage may occur.

The grillage is the most optimal and universal solution for organizing strong, reliable and high-quality foundations for a house, primarily due to the fact that this design embodies the best performance of piles and. Grillages can be installed on reliefs of any complexity with a wide variety of soil characteristics without restrictions on the type and weight of buildings. The only exceptions are solid rocks, where the development of pits or wells is impossible or economically infeasible.

Low grillage arranged on dry, dense and loose soils with minimal influence of flood, storm and melt water.

Raised grillage laid on soils with a low degree of heaving, where significant moistening of the surface layer of soil is possible under the influence of storm, flood and melt water.

High grillage organized on any soil with a medium and high degree of heaving. In this case, the lower edge of the grillage tape is raised at least 10-15 cm above ground level to avoid the influence of stress forces from surface swelling of the soil during frosts.

The choice of grillage type depends on the condition of the soil, local climatic conditions and the weight of the building, taking into account possible snow load. Determining the number of columns, the distance between piles and the width of the monolithic tape are important design indicators. Therefore, it is better to entrust this part of the calculations to specialists. Marking, preparing holes for pillars or laying piles is carried out using the same technologies as for pile and columnar foundations, and pouring the tape is similar to the construction of a strip foundation.

Features of a pile foundation

When building small frame houses, pile construction is recommended. However, when constructing large, tall buildings, the use of this type of foundation is undesirable, since the structure will be exposed to strong winds, as well as many other external factors that can lead to the destruction of the building.

A huge advantage of screw piles is that the construction of a house can be done on a slope

Instructions for installing a pile foundation

The first thing to do is select and mark the area for building a house on stilts. To eliminate possible problems in the future, you should obtain a plan for underground and power cable networks.

Installation of piles. There are several simple ways. For example, we screw piles into the ground until they stop by hand, or we drive them mechanically. In the intended location for installing the piles we make a small recess, the so-called guide. Next, the support is erected. The support should be installed strictly vertically.

The support lever is a crowbar installed in the support hole on which the pipe is installed. You should initially install the supports strictly vertically, since it will not be possible to correct them in the future. Therefore, when screwing in, you should carefully monitor the position of the support and, if necessary, adjust vertically. In some cases, you need to manually prepare a recess of up to 50 cm, or maybe more - this problem can arise in the presence of stones or hard soils.

The depth of immersion of piles is calculated individually according to the project and should not exceed the level of hard soil rocks.

Rules for working with screw piles

Upon completion of the installation of the supports, they are leveled in height and, if necessary, trimmed with a grinder; this should be done in order to eliminate the horizontal subsidence of the slabs and beams of the base of the house. The height of the foundation screw piles above ground level should not exceed 60cm. Next, the structure is filled with concrete in order to obtain the strength and reliability of the foundation of the future house. It is also important to remove excess air from the concrete surface, as this can lead to future deformation of the concrete slab. The next step is to weld the ends and tie them with timber. You can also use metal channels, replacing timber with them. When using a channel, the heads can be eliminated, which will significantly reduce the cost of the future home.

When constructing a pile foundation, it is strictly prohibited:

Lengthen or correct twisted piles;
Use damaged piles;
Immerse the piles to a depth of less than one and a half meters from the top ground level;
Allowing a vertical slope of more than 2 degrees;
When screwing in, adjust the piles to the horizontal level.

It is very important to carefully familiarize yourself with the technologies and rules before installing a pile foundation. In the future, this will definitely bring great benefits, and you will also get a high-quality and durable foundation for your future home.

The installation step of the screw piles determines how reliable the foundation of the house will be. The weight of the building is transferred to the supports, through which the loads are transferred to the ground, so the correct assumption is that the more screw piles are located under the house, the less pressure they will exert on the soil foundation. Thus, we can conclude that the step between the foundation supports directly depends on the total mass of the building, including useful and temporary loads.

Optimal distance between piles

Screw metal supports for a frame or timber house are installed in increments of no more than three meters. But often it is reduced to 1-1.2 meters. This parameter depends on the total magnitude of the loads and soil properties. Calculation helps to find out a more accurate distance, which may not be performed for temporary and non-critical buildings.

Piles are installed evenly along the length of the wall, always at internal or external corners, at the junction of load-bearing walls and the location of critical components, as well as under the pillars of the frame structure.

When determining the pitch of the screw supports, you should take into account the length of the grillage beams, since both ends must rest on the head of the screwed pipe. This applies to both frame and timber houses. But in the case of constructing a concrete grillage, this factor is not taken into account.

If a slab foundation is planned for the foundation of the house, then the location of the screw piles is determined by the design documentation. This design requires a slightly more complex calculation, but the principle remains the same - the supports are placed under the load-bearing walls or columns of the frame house.

Placement of screw piles in plan

Correctly placed supports will help maintain the integrity of the house. With their help, the load will be evenly distributed under the building area, and therefore unwanted subsidence will be avoided. A house with complex contours in plan requires special attention, especially the corners and junctions of the walls. Installation of screw piles under them is mandatory.

Pile placement patterns depend on the design features of the house. There are four types of their arrangement in plan:

single - under the vertical posts of a frame house, at corner points, under load-bearing walls (equidistantly in increments of no more than 3 meters);
strip - under load-bearing walls, but, unlike single screw piles, with a shortened pitch, often reaching up to 0.5 m. The arrangement of supports in the form of a tape allows the foundation to accept and distribute more significant loads;
cluster - under heavy single or group structures, as well as under massive equipment. The step, in this case, does not matter, since the screw piles at the installation site can be placed too close in a chaotic manner. The main condition is that they must be present along the entire perimeter and area of a small-sized slab grillage required for installation, for example, of a heavy load-bearing column of a frame building;
continuous, called a pile field. The supports fill the entire area under the foundation slab in increments of about one meter. This placement of screw piles in plan is practiced when designing heavily loaded objects or when building on soils with too weak bearing capacity.

For private houses and small buildings, as a rule, the first two types of screw pile arrangement are used.

Calculation features

When determining the pitch of screw piles, reasonable considerations should be followed. Too large a distance between the supports will lead to subsidence of the house, and a small distance will lead to overexpenditure of material resources. In this regard, experts recommend performing calculations that take into account:

actual mass of above-ground structures and finishing materials;
approximate weight of furniture and equipment, including communication systems;
snow and wind loads;
bearing capacity of the soil (the exact value is taken by calculation);
technical characteristics of screw piles;
safety factor.

The payload when calculating the pitch of pile installation is determined according to the relevant SNiP or technical specifications. For example, for a one-story residential building it is about 150 kg per square meter of area. Indicators of snow and wind loads are taken from reference books, depending on the region of construction of the facility. And the safety factor, as a rule, is 1.1-1.25.

The bearing capacity of piles is directly proportional to the diameter of the metal pipe, the number, shape and size of the blades.

The calculation of the number of screw supports required for the foundation is quite simple. Their number and the linear dimensions of the load-bearing walls in plan influence the installation step of the piles. The total load is divided by the load-bearing capacity of one metal support. The result is the required number of piles, which are distributed with equal spacing along the perimeter of the building envelope.

Another calculation option comes down to determining the forces acting on one linear meter of grillage. To do this, the total load is divided by the length of all load-bearing walls, after which the result obtained is again divided by the load-bearing capacity of the selected screw piles. The result is the number of supports required to support one meter of strapping under load. Further calculation comes down to finding out at what step the piles should be installed so that the foundation can withstand the calculated forces. This method is intended for massive buildings.

The bearing capacity of metal screw piles is indicated by the manufacturer in the technical documentation. Approximate parameters can be found in the table.

The next step after calculation is the schematic placement of screw piles in the foundation plan. As noted earlier, they must be present in corners, under columns and at the junction of load-bearing walls. The remaining piles are distributed evenly between the main supports. This way the exact pitch between the screw piles is determined.

Visual calculations

For example, you can take the calculation of a one-story house made of timber measuring 6*6 meters. The volume of wood is calculated depending on the thickness of the walls and the height of the building, taking into account the roof. Let's assume that it is 20 thousand cubic meters. We multiply the number by the weight of one cube of wood (in our case – 800 kg). As a result, we get a total load of 16 tons. Here we add the weight of roofing and finishing materials (let's say 2 tons).

payload – 36m2*150kg/m2, which is 5.4 tons;
snow load – 36m2*120kg/m2, which is 4.32 tons.

After summing up, we get the figure - 27.72 tons, which we multiply by the safety factor - 1.1. As a result, when calculating the number of screw piles, we use the load indicator - 27.72 * 1.1 = 30.492 t. Taking as a basis piles with a diameter of 89 mm with a design load of 2 tons, we obtain the minimum number of piles - 30.492/2 = 16 pieces, which are evenly distributed along the outer perimeter of the house. Additional supports can be installed, for example, for floor joists.

For a two-story house, the payload doubles.

The above calculation is not accurate. In each specific case, additional efforts arise, internal load-bearing structures, poles, equipment, etc. appear. Often finishing materials significantly increase the weight of the house. All nuances must be taken into account in an individual project that establishes the pitch of foundation supports.

Frame houses are most often built using a pile-screw foundation. This technology saves time on foundation installation and does not require excavation work. What should be the distance between screw piles for a frame house? What subtleties do you need to know before starting work? Let's try to figure it out.

Features of a pile foundation

This type of foundation is not suitable for the construction of buildings made of heavy materials (brick, concrete, etc.). It is intended exclusively for the construction of light structures, such as frames.

The design is easy to install. The work is carried out according to the following algorithm:

Site selection and cleaning. Trees, bushes and grass are removed. There should be no communications in the work area.
Marking the territory. This is necessary for the most accurate installation of piles. The marking is carried out according to a pre-prepared project, where the location of each support is indicated in detail. The maximum permissible deviation from the design is 2 cm.
Installation of piles. According to the markings, a small recess is made for each pile - 15-20 cm, to make it easier to install the support. We install the pile and screw it in.
Installation of piles is painstaking work. To do this you need to involve 3-4 people. First of all, the support needs to be assembled: in the upper part of the piles there is a special hole into which a crowbar (3 cm in diameter) is inserted. A lever is then mounted on it - it helps to simplify the process of screwing in the support.
A pipe 3-3.5 m long is used as a lever. The longer the lever, the easier the support rotates. In addition, it is important that the piles enter the ground smoothly. For this, a building level is used, which is applied to the post while screwing.
Next, we place the support in the prepared recess and begin to screw it in. To do this, two people grab the lever on both sides of the support and move in a direction against the axis. In one full rotation, the pile plunges into the ground approximately 20 cm.

Important! If the pile enters the ground unevenly, it must be leveled.

Therefore, the level of entry should be monitored throughout the entire process. It is important to remember that the deeper the support is immersed in the ground, the more difficult it is to level.

It happens that the “first” steps are difficult, and the screw does not want to turn. In such cases, the recess for support increases by 10-15 cm, and some kind of weight is hung on the levers as an additional vertical load. When the support rotates easily, the load can be removed.

Working with piles

After installation of screw piles, additional work is carried out. First of all, you should make sure that all supports are installed level. There should be at least 60 cm from the ground to the zero level of the house. We align all the piles so that they are in the same plane. For this you can use a grinder.

The mixture is poured into the internal void of the pile, it is also necessary to lay reinforcement, this will give the structure reliability. For this, a cement-sand mixture is prepared. Its consumption is 35 kg per 1 pile.

The final stage of mounting the supports is welding the ends. After this, timber tying is performed. If you use a channel instead of a beam, then you can do without the heads. This will help you save a lot.

Working with a pile-screw foundation excludes the following actions:

Adjusting the piles to the same level during screwing. This work is carried out after the installation of all supports is completed, otherwise it may provoke subsidence of the foundation in the future;
Lengthening unevenly screwed in piles;
Installation of supports less than 1.5 m into the ground;
Creating preparatory holes for supports in the ground deeper than 50 cm;

It is impossible to install supports with damaged coating. This will lead to corrosion and destruction of the piles.

Determination of soil bearing capacity

To install a pile-screw foundation, you need to know about the bearing capacity of the soil. The design of the house, including the foundation, is created on the basis of this data. Finding out the structure is not difficult; to do this, you can look on the Internet or ask your neighbors.

Even after finding out this information, it is better to check the soil on the site yourself. To do this, you need to take an old fishing drill and drill a hole in the far corner of the site. This will help to clearly see the condition of the soil: its moisture content, the depth of the horizons, etc.

Ideal pitch between supports

The pitch of screw piles installed under a frame house is up to 3 m. Most often, this figure is reduced to 1-1.5 m between supports. This is influenced by the characteristics of the soil, mass and purpose of the structure. It is necessary to calculate the distance between piles for each house individually.

Important! Piles must be evenly spaced throughout the structure. Located on external and internal corners, under load-bearing walls.

The distance between the piles is also determined by the length of the grillage, since both ends must rest on the head of the support. This is not taken into account only if a concrete grillage is installed.

It is a little more difficult to calculate the placement of supports for a slab foundation. As a rule, special design documentation is used for this. But the principle of placing supports does not change: they are placed under load-bearing walls and frame columns.

Placement of supports in plan

Correct placement of piles is necessary to maintain the integrity of the frame house and avoid subsidence. This is especially true for complex projects: projects of two-story houses, a building with irregularly shaped walls, etc. The main rule: the load must be distributed evenly.

The location of house supports is of four types:

Single. The piles are located at an equal distance from one another at the corners of the building, under the load-bearing walls, and under the vertical posts of the frame;

Tape. This type of pile-screw foundation can withstand higher loads. The supports are located as with a single type of foundation, only the step between them is shortened;

Bush. This implies a chaotic placement of supports under the foundation of the house. They are mounted in clusters, with most piles located in areas with the highest load (for example, under a room with heavy equipment). Under such conditions, the step between the supports does not matter, the main thing is that they are along the entire perimeter of the slab;

Continuous (in other words, pile field). This type of foundation is relevant for areas with unstable ground cover and for heavy frame buildings. The piles are arranged in a grid around the entire perimeter of the building. The maximum step is 1 m.

Important! The most common types of pile-screw foundations are strip and single. They are provided for in the designs of private houses and small buildings.

Calculation features

Calculating the correct distance between the supports is important for the following reasons: if the supports are too far apart, the building may settle; a small distance between the piles will significantly increase the financial costs of construction. Professional builders recommend taking into account when making calculations:

Weight of the frame structure as a whole;

A lot of furniture, equipment, communication systems;

Safety factor;

Properties of the piles themselves;

Load from wind and snow;

Soil stability.

The calculation also takes into account such indicators as:

Payload. It is determined by the provisions of SNiP (building codes and regulations);

Snow load. It is individual for each region, so you need to find it specifically for your area;

The standard safety factor is always used - 1.1-1.25.

As soon as the calculations are carried out, it is necessary to record the obtained data. For this, a diagram is drawn. It clearly indicates the location of each individual pile on the foundation plan. This will simplify the distribution of supports directly during work. Whatever the result of the calculations, the columns must be located at the corners of the building, in the area where the load-bearing structures meet. The remaining supports are placed under the floor joists of the future house; they need to be distributed evenly.

We carry out calculations

In order to correctly calculate the distance between piles for your frame house, we will clearly consider how to install them, using the example of a one-story building made of wooden beams. Its area is 6x6 m. We calculate the volume of wood, for this we take into account the height of the walls of the house, taking into account the roof and their thickness. Let's imagine that we have 20,000 m3.

Payload. 36 m2 (house area) * 150 kg/m2 = 5.4 tons.

Snow load. 36 m2*120 kg/m2 = 4.32 tons.

We sum up all three results and get 27.72 tons. Next, we multiply this number by the safety factor - 1.1. As a result, we get 30.492 tons of load.

In construction we will use piles with a diameter of 8.9 cm. One such support is designed for 2 tons of load. The minimum number of piles is calculated as follows: 30.492/2=16. This is the minimum number of piles that are located around the perimeter of the building. It is also necessary to install additional piles under the floor joists and load-bearing frames.

Important! If the building is 2-story, the load is multiplied by 2.

This is a generalized example of how calculations are carried out, but it does not take into account the individual characteristics of the area and the project itself. It is recommended to entrust this work, as well as the design of the building, to professionals. This guarantees the reliability and durability of the foundation.

Finally

It is simple to build a frame house on a pile-screw foundation, but for its reliability you need to know what distance should be between the supports. We talked about all the intricacies of calculating the step between piles.

As a rule, specialists begin designing a pile-screw foundation by calculating the number of piles, choosing their parameters and placing them on the diagram on the outside and inside of the house. Also, to guarantee quality work, it is necessary to carefully measure the distance between the piles. This whole process can be done independently, especially since there is a simplified calculation of the foundation using piles.

Calculation methods

The main elements of this type of foundation are screw piles made of metal, the length and diameter of which may vary depending on the technological requirements and the expected load that they will have to withstand. In specialized companies and design bureaus, you can order a professional, complex calculation of the pile-screw foundation, which will include various parameters and design features, and also take into account the bearing capacity of the soil on the site allocated for the construction of the future house. We propose to use a simplified option and carry out calculations of screw piles, based on practical experience in constructing such structures.

Grillage options for screw piles

Determining the diameter of the supports

Screw piles, which are used when installing foundations for residential and commercial buildings, have a diameter of 57, 76, 89 and 108 mm. This parameter is selected depending on the weight of the finished structure:

57 mm - used for the construction of the simplest and lightest structures (fences and fences made of chain-link mesh);
76 mm - chosen as the basis for lightweight outbuildings or fences made of wood or corrugated board. The bearing capacity of such elements does not exceed 3000 kg;
89 mm - used where the load-bearing load will not exceed 5000 kg. This is an excellent solution for the construction of a one-story building (frame or panel), baths, summer kitchens, sheds and massive fences;
108 mm - foundation a site for the construction of a house made of foam blocks, wooden beams, frame (1-2 floors) with light weight. The bearing capacity of screw piles of this diameter reaches 7000 kg.

The diameter of the elements depends on the weight of the building

Factors affecting the length of supports

The strength of the future structure depends on the correct determination of the length of the piles, and if these important elements of the foundation turn out to be short, the house may sag under its own weight after it is put into operation. The length of the piles is determined taking into account the analysis of the soil and landscape, namely:

Soil density.
The difference in height between different points on the site.

Soil density

Support immersion depth

Soil analysis is best carried out based on geological studies of the area. If studies of soil characteristics have not been carried out in a given area, then you can use a simplified method to determine its density.

So, you need to dig a shallow ditch (up to 1 m) at the lowest point of the site. If at such a depth you see a clay mass or sand, then it is better to make a choice in favor of piles, the length of which reaches 2.5 m. If you find low-density rocks (peat), quicksand or groundwater, you will have to continue deepening until you reach hard rocks. Piles are installed here, the length of which is equal to the length of the drill.

Here is a table of the density and bearing capacity of various soils.

Type of soil	Dense soil	Medium density soil
Sand (large fraction)	6	5
Sand (middle fraction)	5	4
Sandy loam (dry)	3	2.5
Plastic sandy loam (wet)	2.5	2
Sand (fine fraction)	4	3
Wet sand (fine fraction)	3	2
Clay	6	2.5
Clay wet	4	1
Loam	3	2
Loam wet	3	1

The difference between the heights of the site

As mentioned earlier, in order not to make a mistake with the piles and correctly calculate their length, it is necessary to determine the difference in height of different points on the site. If you are convinced that such a difference exists and, according to the density of the soil, piles 2.5 m long are suitable, then they must be mounted in the very top row.

Those supports that will be fixed in lowlands should be longer by the difference in height between the points of their installation. The difference is calculated using a water level or level using a plumb line and tape measure. If there is a significant difference in height (more than 0.5 m), it is recommended to add 50 cm to the resulting length of the foundation piles, since in the lowest places their height may not reach 20 cm.

Accounting for height differences

Calculation method

The number of screw piles is calculated taking into account the dimensions and weight of the house that will be installed on the foundation. As a rule, the distance between piles can be:

up to 2 m if a structure is built from aerated concrete and foam concrete blocks or slabs;
up to 3 m, if it is planned to build a wooden house from timber, logs, etc.;
up to 2.5 m - also chosen for wooden structures. They also work with such piles in regions where there is a large wind load;
up to 3.5 m - for the construction of lightweight fences and fences.

Construction of a house from timber

To correctly determine the number of supports for a pile-screw foundation, the following operations should be carried out:

draw up a project for the future foundation or first level of construction;
place screw supports at each corner of the future building;
install piles where the load-bearing partitions of the house will intersect;
between the located piles it is now necessary to install additional piles along the perimeter of the load-bearing walls with the condition that the distance from one to another element does not exceed what was previously recorded (taking into account the weight and type of building);
the remaining space for the foundation is filled with piles so that the distance between adjacent supports does not exceed that specified in the calculations (2 - 3 m);
where a stove or fireplace will be installed, provide at least a pair of screw supports, again, taking into account the size of the heating structure, otherwise a critical load on the foundation cannot be avoided;
in case a terrace or any other extension is built, the locations for fixing the supporting elements are designated according to the previously agreed upon principle, taking into account the optimal step distance;
Now that the distance between the piles has been determined, all that remains is to count all the screw supports marked on the plan diagram.

Calculating the grillage

The pile base can be constructed from only supports, on which the lower frame of the building is laid.

To ensure that the load on the supports from the weight of the structure is distributed more evenly, they resort to making a grillage.

A grillage is a beam or reinforced concrete slab that horizontally connects the tops of each screw element. Pile-grillage foundations are equally well suited for the construction of wooden and foam block buildings. The strip grillage can be monolithic or prefabricated, the main thing is that it is cast from concrete, the grade of which is not lower than 150.

In order for the grillage to be properly constructed and create a strong connection between the screw elements, you need to correctly calculate its dimensions. There are a number of special calculations, but we will limit ourselves to the minimum dimensions of the binding tape:

Foundation with reinforced concrete grillage

Height – 30 cm.
Width – 40 cm.

To give the grillage the necessary rigidity, it must be reinforced with longitudinal and transverse reinforcement (10-12 mm in diameter). The rods are connected using wire according to the principle of an armored belt. The distance from the reinforcement to the edge of the grillage must be at least 2.5 cm so that the metal rods are completely sealed with concrete mortar and are not subject to corrosive processes.

The connection of the grillage with the supports can be rigid, when its reinforcement is connected to the pile rods, or loose, when the grillage lies on the foundation supports without additional support. In both cases, the load is distributed evenly between the piles.

The content of the article

How to calculate the distance between piles? This question worries both builders who are responsible for the quality of their work and customers purchasing piles. Moreover, the former want to dot the area with a dense palisade of supports, and the latter demand a report on each used pile.

In the end, both are wrong. After all, the distance between the piles is not determined by the opinion of the foreman or the desire of the customer. This value is included in the project by the architect, who determines the minimum distance based on complex calculations that take into account the weight of the constructed structure, the depth of soil freezing, the load-bearing capacity of the pile, and even the type of support. And in this article we will introduce our readers to the basics of such calculations.

We calculate the required number of piles - the basics of the process

Where does the calculation begin? Of course, from determining the bearing capacity of the soil. After all, it is the soil that supports the entire weight of the structure. Consequently, the less stability of the soil, the more supports are needed and the smaller the distance between supports.

The bearing capacity of the soil is determined in two ways - by analyzing a soil sample and analyzing the bearing capacity of a control pile. Both options are practiced only in the process of geotechnical research. This data cannot be obtained under domestic conditions. Although the bearing capacity of the soil can be determined by its type from special tables.

The next step is to determine the total weight of the structure. After all, the main factor determining the load on one pile is the totality of the masses of building materials, furniture and even snow cover on the roof of the building.

By determining the total weight of the structure and knowing the bearing capacity of the soil, you can calculate the area of the foundation base. For these purposes, use the formula:

Where S– area of the sole (in cm2); M– weight of the structure (in kilograms), N is the bearing capacity of the soil (in kg/cm2).

As a result, knowing the total area of the base, you can calculate the number of bored piles or screw supports, or driving rods, or any other vertical elements of the pile foundation.

For example, if the weight of the house is close to 150 tons, and the load-bearing capacity of the soil is 15 kg/cm2, then the total area of the base will be 10,000 cm2 (150,000 /15).

Next, you should select the type of support and calculate the number of piles based on the area of the lower part. So, for a 40-centimeter cylindrical-type bored support, the area of the bottom end is 1256 cm2, and for a classic BC108 screw pore with a blade diameter of 30 centimeters, the bottom area is 706 cm2. Well, the TISE support with a half-meter extension at the bottom has a 1960-centimeter base area.

Thus, the 150-ton weight of the structure will be supported by 15 BC108 supports (10000/706) or 8 bored supports with a base diameter of 40 centimeters (10000/1256), or 5 TISE supports with a bottom part of 0.5 meters in diameter (10000/ 1960).

Determining the distance between the piles

Further calculations to determine the distance between the piles look even simpler. After all, the value we are interested in must be between two extreme values - the minimum and maximum possible distance between the piles.

Simply put: piles cannot be mounted closer than the minimum distance between supports (placement step) and it is not advisable to immerse them further than the maximum distance between supports. And to understand the essence of determining the “step” of piles, we must understand the definition of the minimum and maximum values of this parameter.

The smallest distance between piles is determined by the thickness of the compaction in the soil resulting from the installation of the support. Simply put, when driving a pile or drilling a shaft or screwing a support into the ground, the space around the plunge point is compacted. Therefore, all piles are mounted in increments equal to at least three support diameters.

That is, the minimum distance (step) between the supports is equal to three diameters of the piles. And it is not recommended to install piles closer than this distance. Although there are exceptions to the rule. For example, inclined piles are mounted in increments of one and a half diameters of the support.