Pile foundation with grillage. Do-it-yourself pile foundation with a monolithic grillage: types - material and grades of concrete for the foundation What is a monolithic grillage

A sample of a pile foundation with a monolithic grillage

In some cases, especially when unstable or too wet soils with large height differences, conventional strip foundations are not able to withstand large loads.

In such cases, the use of pile foundations with grillages is justified, because then the bearing element of the building - the grillage, takes on the entire load from the structure and evenly distributes it to the supports.

Moreover, the length and thickness of the supports, as well as their design, can differ significantly in the structure and shape of the grillage. Rigid and durable monolithic grillages have now become popular, which, due to reliable reinforcement and the use of high-quality building materials, can “extinguish” small soil movements, swelling of individual sections and washing away with groundwater.

The device of a pile-monolithic foundation allows its use on slopes, permafrost, weak, bulk and other soils.

Why a pile foundation with a monolithic grillage?

1. Low cost of financial costs for mechanisms and building materials;
2. Minimum terms of construction of the building;
3. Minimum consumption of concrete for pouring supports;
4. Transport costs are reduced by at least half;
5. A small drawdown of the building due to the boundary depth of immersion;
6. Minor expenses for land works;
7. You can build a foundation yourself without the use of mechanized equipment;
8. A monolithic grillage can be made in winter, using special cements and adhering to technology.

Variants of pile-monolithic foundations

Low pile foundation

Hanging grillage. This is the base, which provides for the presence of an air cushion inside with a height of 70-100 mm. In fact, the floor of the building hangs above the ground and is mounted on supports. The advantage of the design is the minimal impact of the soil on the lower part of the concrete base.

• Seal of piles in a monolithic basement. There is no longer a gap between the ground and the base, but you can make a basement of low height. The grillage in such cases can be erected from concrete, reinforced concrete, steel, wood, other building materials, and be sure to make reinforcement.

Preparatory work during the construction of a monolithic pile foundation

1. Carefully align the heads of the installed piles horizontally;
2. Rinse the top, clean and dry;
3. Build formwork around the perimeter of the future monolithic grillage;
4. Make protection from concrete mortar if the formwork is temporary;
5. Pour the monolithic base with concrete mortar evenly horizontally.

How to build a pile foundation with a monolithic grillage

The device of this type of foundation is extremely simple, but at the same time it is distinguished by reliability and quality. After all, each element here is made from concrete, reinforcement is used in horizontal and vertical belts. Not surprisingly, the arrangement of such a foundation is considered optimal even in mountainous areas with a high probability of seismic activity.

Making such a foundation with your own hands is not difficult due to its simplicity. A problematic place is the choice of supports and the type of monolithic grillage. Therefore, the phased technology for the construction of a pile-monolithic foundation, taking into account its device, is as follows:

• Development of a detailed drawing of the future building. This stage should include a detailed map of the area, which shows the soil structure, slope and natural relief. Also, the project should indicate the characteristics of the building itself, its mass, structural elements, dimensions and all necessary sections;
• Carry out drilling of wells in accordance with the developed project to a predetermined depth. If the foundation device provides for the use of driven or screw piles, then they must be installed strictly vertically in the specified places;
• After mounting the supports, you need to make a carrier formwork on top. Here it is necessary to take into account a number of features. If the formwork is provided for a shallow monolithic grillage, then the formwork must be made with a sufficient recess to the ground level. If the foundation is of a hanging type, then the formwork is made U-shaped with a width the thickness of future load-bearing walls;
• After installing the formwork, it is necessary to pour the structure with concrete, starting from the piles and ending with the monolith in separate horizontal layers;
• It is necessary to leave the concrete to dry and gain the necessary design strength, and in a few weeks to begin the construction of the bearing walls of the building.

How to choose piles

Types of pile foundations: a - pile-racks; b - hanging driven piles; c - hanging stuffed piles; 1 - driven piles; 2 - grillage; 3 - stuffed piles

On the market of building materials for pile-grillage foundations, you can buy piles of various designs and bearing characteristics.

Only when choosing them, you need to remember about the performance characteristics of the products. They differ in the following indicators:

• Material;
• Mode of production;
• The shape and dimensions of the longitudinal, cross section;
• Soil immersion method;
• Degree of protection from external influence;
• Bearing characteristics of supports.

How to make a load-bearing monolithic grillage

Monolithic pile foundation grillage

Considering that a monolithic grillage has a large mass, it differs in a feature during installation. After all, a huge mass of reinforced concrete of the grillage itself and, in fact, the bearing walls and ceilings of the building, will press on the supports.

Therefore, in order to ensure maximum structural strength and the ability to withstand seasonal soil movements, reinforcement is indispensable. How to do it right?

1. Support reinforcement. If the supports are made at the construction site, then it is necessary to install rigid vertical reinforcement bars inside the concrete formwork, interconnected by several reinforcement belts. They need to be done every 50 cm, connected with bolted joints. The vertical edge of the reinforcement should protrude beyond the pile to a height of at least 15-30 cm.
2. Reinforcement grillage. Considering that the monolithic grillage has a huge mass, then the entire horizontal belt is reinforced. For this, a uniform arrangement of belts is provided with an interval of 10 cm in height and in increments of up to 50 cm vertically. Then all the belts are connected to each other, as well as directly to the reinforcement of the supports themselves.

What pile material is best for a pile-monolithic foundation?

Foundation from asbestos-cement pipes

Wooden bars. Their length is 8.5 meters, the diameter is up to 34 cm, the shape is round, less often rectangular. For their production, fir, spruce and pine are used, less often oak and hornbeam. They are rarely used due to the high cost of building materials, as well as the susceptibility of wood to decay, short service life and low reliability.

• Reinforced concrete supports. They are produced in the factory or manually from cement grade M-200 and higher, the service life is from 100 years. For installation, you need to use special equipment and connect additional personnel;
• Steel. Such supports are well-deservedly popular, but they are expensive, they are susceptible to corrosion, and due to their large outer diameter they are distinguished by a huge mass. Also here you need to use special anti-corrosion materials.
• Asbestos pipes. Relatively inexpensive, easy to install, but you can’t do without additional reinforcement.

Which piles are better to use in certain conditions

Do-it-yourself construction of a pile foundation with a grillage

Driving supports are made from reinforced concrete, the section is rectangular, less often round, the dimensions may vary. They are used on weak soils in the upper layers, under which there are solid bearing rocks;

• Tubular piles-shells. These are metal supports of a round shape, used for the construction of foundations on soft soils, in seismically active zones and with the possible influence of horizontal, vertical and pulling loads. The tip of steel piles is sharp, sometimes spiral;
• Pyramidal conical piles made from concrete. They have dimensions of 40x40 cm, gradually narrowing to a size of 20x20 cm. They have high bearing capacity, they are used when the top layer of soil has high building characteristics, but its thickness is insufficient to build a reliable foundation;
• Rhombic. More practiced on heaving soils with high ground horizons.

The pile-monolithic foundation is now considered one of the most reliable and practical structures, despite its design and some difficulties in erection.

Pile foundation with a monolithic grillage: device

Pile foundation with a monolithic grillage: device. Pile foundation technology. The choice of piles for the foundation with a monolithic grillage.

When is a pile foundation with a monolithic grillage used?

• How to make a pile foundation with a monolithic grillage?
• Types of piles and their features

Pile foundations, unlike other types of foundations, are able to provide high quality and reliability at relatively low cost and simplicity of design. Features of this type of foundation make it possible to use it not only on normal flat ground, but also under rather difficult conditions, on slopes, permafrost, weak, bulk, sandy, swelling soils. The section of such a foundation is not a monolithic slab or tape made of concrete, brick or stone, but individual pile supports that are driven into the ground to the required depth, and a strapping that serves to fix the piles.

When building a monolithic pile foundation, it is important to monitor the horizontal and vertical structural elements using the building level and level.

One of the used options for such a foundation is a monolithic grillage, which is used for an ordinary (cluster) arrangement of piles.

Advantages of a pile foundation

The pile foundation used for private construction has the following advantages:

• low labor intensity in comparison with other options for the construction of the foundation by about 25%;
• the terms of work are also much less than even during the construction of a strip foundation;
• the consumption of concrete for pouring is not less than for the construction of a base of another type;
• the need for transport work is also reduced by 70-85%;
• the probability of building subsidence during operation is halved;
• a monolithic pile foundation based on a grillage can be erected even in winter, observing the technology;
• the cost of work is reduced by 15-20%.

Variants of a pile foundation with a monolithic grillage

Scheme of the stages of pile formation.

• hanging grillage, the section of which suggests the presence between the grillage itself and the ground of a gap with a size of 70-100 mm, that is, the base of the house, as it were, hangs over the soil. In this case, the negative impact of the soil on the grillage monolith is excluded. A similar method can be used for houses made of any building materials;
• embedment of foundation piles in a special monolithic grillage basement. That is, in this case, there is no longer a gap between the soil and the foundation of the house, but it turns out a basement, which is simply impossible with a conventional pile foundation. The grillage can be made of materials such as concrete, reinforced concrete (preferred option), steel, wood.

To make any monolithic grillage foundation, it is necessary to carry out the following preparatory work:

• pile heads must be cut to the required height;
• the upper part is washed, cleaned, dried;
• formwork is being built;
• for removable formwork, protection from the concrete composition is performed;
• a monolithic grillage is being poured. In this case, the solution is laid in horizontal even layers over the entire surface of the grillage.

How to make a pile foundation with a monolithic grillage?

Making a pile foundation with your own hands is not so difficult, which greatly distinguishes it from other types of foundations for a house. The procedure includes several steps:

Scheme of a monolithic grillage: 1. Pile. 2. Monolithic grillage. 3. Waterproofing. 4. Ventilation.

• first you need to draw up drawings, which will indicate the section of the future base, markings, data for the start of construction;
• according to the markings applied to the ground, pits are drilled for future reinforced concrete piles. If there are already ready-made factory piles, then they must be simply hammered into the ground to the specified depth using a pile hammer;
• after that, formwork is made from edged wooden boards or using a special removable formwork;
• if a monolithic recessed grillage is to be mounted, then it is necessary to make a trench for subsequent pouring;
• using the prepared concrete solution, the grillage and piles are poured;
• the solution should be left for up to 1 month for complete drying and strength gain.

When performing work, it is necessary to ensure that the section of the drawing completely coincides with what design is obtained in reality.

Scheme of grillage types.

• reinforced concrete piles in accordance with the type of soil and features of work on the site;
• sand and gravel for cushioning at the bottom of wells (if necessary);
• equipment for digging wells and trenches (if a pile foundation with a buried grillage is planned);
• concrete mortar, which is required for pouring the grillage and piles;
• edged boards for formwork, nails for fastening them.

The process of building the foundation is not so complicated, in this case there is no need to have heavy construction equipment, and the materials themselves are not as expensive as for a conventional monolithic foundation or for a strip one.

Types of piles and their features

In order for the pile foundation to turn out to be of high quality and reliable, it is necessary to determine exactly what type of piles will be used for work. Today, a variety of options are used, which have a length of 3-6 m. They also differ in the following indicators:

Scheme of a pile monolithic foundation.

• material of manufacture;
• mode of production;
• the shape of the longitudinal, cross section;
• method of immersing a pile into the soil.

According to the method of piling:

• reinforced concrete bored piles mounted in already drilled wells;
• screw piles with drills;
• special driven piles, which are immersed in the soil by indentation or vibration immersion;
• reinforced concrete, concrete stuffed piles, which are laid in drilled wells, after which they are poured with concrete.

According to the impact method, all piles can be divided into:

• hanging, which transfer the load according to the principle of soil friction along the walls;
• racks that transfer the load from loose soil to solid. This option does not give a draft of the structure.

According to the location method, all piles for the foundation can be divided into:

• single piles acting as supports separately;
• combined into tapes, which are placed along the perimeter of the walls to evenly distribute all loads. Such tapes are placed in one or more rows, depending on the requirements;
• combined into bushes, that is, piles located under the supporting columns for frame structures. With a similar cluster arrangement, a monolithic grillage can also be used, which improves the quality and reliability of the structure.

Steel, wood or reinforced concrete?

As materials for supports are used:

1. Smooth poles made of wood, the length of which is 8.5 m, and the diameter is up to 34 cm. For the manufacture, wood species such as fir, pine, and spruce are used. This option is the cheapest, but it is rarely used. This is due to the fact that piles are highly susceptible to rotting, their service life and reliability are low.
2. Reinforced concrete supports are made of concrete grade 200 and higher, their service life is from 100 years. They are easy to install, but manufacturing on site requires special equipment and personnel.
3. Steel is used most often, since metal piles are stronger, more stable and durable. But their cost is high, with a diameter of more than 10 cm, special equipment is required for installation. In addition, before installation, it is necessary to treat the metal with anti-corrosion compounds.
4. Asbestos-cement pipes are relatively inexpensive, but reinforcement is required during installation. It is performed when pouring piles with concrete mortar.

Consider which piles can be used under certain circumstances:

Scheme of pile-grillage foundation.

• driven supports are made of reinforced concrete, their cross section is usually square, there are two varieties: with a broadening of the trunk in the lower part and ordinary ones. Such a pile foundation is used for weak upper soil layers, under which there are layers with sufficient bearing capacity;
• tubular, shell piles - metal supports that are used in construction on rather weak soils, in seismically active areas, in the presence of horizontal, pulling, vertical loads. The ends of such piles are often conical;
• pyramidal piles, which have a section of 40 * 40 cm at the head and 20 * 20 cm at the sharp end, have the highest bearing capacity. They are used when the upper parts of the soil have better building properties than the lower layers. ;
• diamond-shaped are used for heaving soils. With the help of its shape, the pile compacts the soil.

Today, such a type of foundation as a pile is increasingly used, the varieties of which allow it to be used in almost any conditions. Such a foundation is indispensable when building a small private house on difficult soils, under conditions in which other types of foundations simply cannot cope with all the necessary tasks, or their construction is too costly and complicated. To connect the piles from above, a concrete grillage is used, including one of its varieties - monolithic.

Monolithic pile foundation: how to do it?

The monolithic pile foundation is applicable for weak, bulk, sandy, swelling soils. Such a foundation allows you to make the design more reliable.

Features of a monolithic foundation on piles

Taking into account the fact that the construction of the foundation of any building is the most expensive stage of construction, it is on it that you can save a lot if you correctly determine the type and layout of the buried part of the structure. A monolithic pile foundation from the standpoint of reliability and reasonable cost is one of the best options. What it is, when it is advisable to mount it, whether the technology allows you to do all the work on your own is the topic of this article.

Features of the foundation of piles

Before dealing with the advantages of such a base, the specifics of its installation and all other issues, it is necessary to clarify the terminology. It is the similarity of names that often causes confusion. In construction, 4 “basic” types of foundation are known - tape, slab, pillars and piles. All other options are nothing more than derivatives (modifications of those indicated).

Firstly, they differ both in execution and installation technology. Screw piles, which are often used in low-rise (frame) construction, may have a cast or welded pointed part. There are bored supports. Work with such piles is carried out only with the use of technology.

Secondly, free-standing monolithic pillars by themselves do not ensure the stability of the foundation. They must be connected into a single circuit, that is, rigidly fastened together. Several strapping technologies are practiced. For example, a pile foundation with a grillage. But here, too, there are options that differ in the specifics of mounting the tape - with a recess or above the ground.

The type of pile foundation in question is a combination of poured supports and a monolithic grillage. Let's look at this type of foundation in more detail.

When it is advisable to build a monolithic grillage foundation on piles:

• If construction is carried out on problematic soil.

In such cases, a slab base can also be used, but its price is much higher, and the installation technology is more complicated. First of all, due to the calculations of the load and the thickness of the support. With regard to the pile foundation, you only have to take into account the level of freezing. The pits are drilled so that the lower cut of the monolithic column is at least half a meter below this mark. Since in our country, developers are guided by 1.8 - 1.9 m, a trunk of 2.5 m, as a rule, is enough for monolithic piles.

• If in the process of work all operations are planned to be done independently.

Even such convenient piles as screw piles cannot be installed by yourself, without 1-2 assistants. But it is not difficult to equip monolithic supports with your own hands.

Do-it-yourself installation steps

Many types of foundations can be built independently. And this, when describing construction technologies, is positioned as a significant plus. The author will not argue with these statements, but wants to note that the design of a pile foundation should still be entrusted to a professional. If we take into account what problems the owner will have to face when errors are made in independent calculations (for example, when determining the layout of supports and their cross section), then the cost of specialist services will not seem so high. Therefore, further - only a general algorithm for the installation of piles and a monolithic grillage.

1. Preparation of the territory.

A lot is influenced by whether the project provides for a basement (basement) floor. The level of elevation of a monolithic grillage, and in fact a tape of a small section, depends on this.

2. Drilling holes.

It is produced according to the design scheme for arranging piles. The section of monolithic supports can be any - square, circle, rectangle. To reduce the volume of earthworks, it is advisable to involve equipment at this stage. Renting a special / car (in everyday life - a yamobur) will be inexpensive. The approximate price of its operation for an hour is about 1,430 rubles when preparing shafts for supports up to 3 m deep. These one and a half thousand will significantly reduce the time to prepare for laying a pile foundation. And what is important - this technology is guaranteed to provide a strictly vertical orientation of the filling columns.

If it is planned to equip a monolithic buried grillage, then first the soil is excavated under it. And only after the trench is ready, you can start drilling the pits.

• As with the construction of any foundation, a “cushion” is arranged at the bottom of each trunk, which compensates for the impact of the soil (during its movement) on the supports. The loaded ASG must be well compacted.
• When erecting a monolithic base, the solution is always poured into the mold. Mounting it from improvised material with a large length of piles is quite problematic. That is why, in case of independent production of work, it is more expedient to choose the option with a round section of the pillars. As a formwork for foundation piles, it is more convenient to use asbestos-cement pipes. They are easy to cut and put into prepared shafts.
• The method of reinforcement is selected depending on the diameter of the supports. Either a vertical frame is assembled, or 3-4 rods are inserted into the pipes, after pouring part of the solution.

A pile foundation with a monolithic grillage is a single, rigidly connected structure. To ensure reliable fastening of the posts with the tape, 1-2 bars are laid so that their ends rise above the sections of the supports. They will act as connecting elements. Since when pouring a monolithic grillage into the mold, a frame is also installed, then the reinforcement of the piles is fixed on it.

Nothing complicated, but it is necessary to take into account some points. Firstly, it is poured in parts, and each layer is necessarily compacted. Secondly, if a monolithic pile is mounted, then immediately. You can't leave it unfinished the next day. Given the small cross section of the pipes, when preparing the concrete mixture, it is necessary to use a filler of fine fractions. Such a composition in a limited space is easier to ram.

5. Installation of a monolithic grillage.

This work is not much different from pouring a traditional tape. The scheme is simple - formwork + reinforcement frame + mortar. But there are a number of features. Most of all questions are caused by the level of deepening of the monolith. In practice, the thickness of the "cushion" (about 15 cm after compaction) and the height of the reinforced concrete contour (another 30 cm in the ground) are taken into account. For a monolithic grillage is quite enough.

• It is not necessary to make a deeper grillage in order to equip a spacious basement, as this will increase costs. It is more expedient to raise the piles, and lay out the walls of the basement from bricks.
• When installing a reinforcing frame in a mold, it must be understood that during operation, the artificial stone of the grillage may partially crumble. Therefore, the bars should not be located closer than 50 mm from any cut of the monolithic contour.
• Composite products cannot be used to reinforce concrete, especially when building a foundation - neither for piles, nor for grillage. Manufacturers heavily advertise the benefits of plastic fittings, but at the same time they ignore the fact that its reliability has not yet passed the test of time - the material is relatively new. Therefore, it is clearly too early to talk about a 100-year guaranteed suitability of such a bar.
• When knitting the frame, welding should not be used - only manually. A sharp increase in temperature in the working area changes the structure of the metal, and such reinforcement becomes less reliable.

No specialist will name the exact numbers. The price depends on so many factors that the final cost of such a foundation varies widely. For example, what brand of cement was used, the section of the bar, the dimensions of the grillage, the length of the monolithic piles?

If we focus on the prices of specialized organizations (averaged data), then a shallow tape will cost 2,780 rubles / rm, and each monolithic pile - about 1,760 rubles. If you do everything on your own, then the cost will decrease by about ⅓.

Do-it-yourself monolithic pile foundation with a grillage, step by step instructions and tips

Preparation of the territory, installation of piles and installation of grillage. Prices of specialized organizations and the cost of building a foundation on their own.

Pile foundation with a monolithic grillage: features and applications

At the very beginning of construction work, many are trying to decide on the future fundamental structure, the foundation is an integral part of the building, and not only the reliability, but also the strength of the entire structure depends on it. Most developers choose a pile foundation with a monolithic grillage, and this is not without reason, it has proven its strength and durability over time, in comparison with other options for integral foundation designs.

Characteristics of a pile foundation with a monolithic grillage

So what is a pile foundation? This is the foundation when the entire load from the construction is placed on piles. When forming the foundation, screw or driven products are used as piles. Quite often in private construction there are foundations made of piles in combination with a grillage.

To understand what a monolithic grillage is, it is worth characterizing it. This is the upper area of ​​the pile foundation, which performs the function of dislocating the load from the bearing parts of the building. The grillage is carried out using slabs or beams, which are brought together into a single system.

Where is a pile foundation with a monolithic grillage used?

Usually, the use of a pile foundation with a monolithic grillage is carried out on problematic (clay) soils. The foundation, made of piles, helps to transfer an impressive load to harder rocks, the occurrence of which occurs much deeper than the surface soil. Piles are successfully built on ordinary, favorable soils.

In the current development, a pile foundation is often resorted to, since it has an increased load-bearing feature. And it is also economical due to the small amount of land work. Most often, such a foundation is found when laying a shield, wooden or frame structure, as well as when building a small building.

What are piles made of?

Piles include elongated steel rods that are screwed deep into problematic soil.

The pile foundation consists of a pile of piles, which are consolidated with a grillage. Piles are reinforced concrete, made of wood and metal.

The use of wooden piles is based on medium and low loads. The material for the implementation of this type of piles are coniferous trees, most often - pine.

Driving wooden piles is carried out by means of a mechanical hammer, diesel - a hammer and a vibrating hammer.

Reinforced concrete piles are created from concrete. Their other name is driven piles.

At construction sites, solid hollow reinforced concrete piles with a square or round section are most in demand.

Piles can be divided into subspecies: friction piles, which transfer the main load exclusively by the side surface, as well as pillar piles, which penetrate deep into the soil through an unstable layer and, reaching a harder soil, abutting against it, delegate the entire load.

Pros and cons of using pile foundations with a monolithic grillage

Advantages of a pile foundation with a monolithic grillage:

• Its uniqueness lies in the fact that it can be formed on various soil types, except for igneous or sedimentary soil.
• Minimal waste of time for earthworks (this is the most time-consuming and difficult interval in construction).
• Forming a pile foundation can be done even in the cold season.
• The foundation has a guaranteed good bearing capacity.
• The formation of a pile foundation will cost several times cheaper when compared with a strip foundation.

The installation of this foundation itself is not difficult and consists in screwing piles into the ground to the required depth distance, which is prescribed in the construction project. After that, with the help of a grinder, they are cut to the same level.

Disadvantages of a pile foundation with a monolithic grillage:

1. The impossibility of doing without specialized equipment and tools for laying a pile foundation.
2. The impossibility of installation on rocky ground and where there is a solid layer of stones and limestone.
3. When laying such a foundation, you will have to abandon the construction of an insulated basement.
4. Piles cannot be built next to the object.
5. Difficulty in performing calculations.
6. Inability to control the screwed pile for damage.

Pile foundation construction technology

If, when organizing a columnar foundation, there is a need to dig a trench, build a formwork, and then backfill the sinus, then the installation of a pile foundation with a monolithic grillage is much simpler and more technologically advanced.

But how to make a pile foundation with a monolithic grillage? Visually it looks like this:

• Well drilling is organized to the estimated depth distance by means of a hand drill.
• Formwork is being set up, which should be slightly higher than the surface, by about three hundred millimeters. This is necessary for the convenience of pouring the concrete mixture into the drilled well.

Well drilling

The required number of piles that will be involved is calculated. Their number can be calculated based on the weight of the future structure and the total load. The size of the internal piles will be calculated based on the load that the wall partitions, floor and roof create.

When making calculations, one should take into account the fact that a hand drill has a maximum diameter of three hundred millimeters. It is sold at any construction market or store.

The length of the rod at the drill is adjustable, which allows drilling wells up to five meters. The location of the cutting blades at the drill is designed so that the applied force during operation is negligible. In industry, they began to manufacture hand drills that can significantly broaden the lower region of the well. In addition, during drilling, the formation of a support for the pile occurs, which in turn helps to save on concrete, since the number of required piles is reduced.

Reinforcement and pouring concrete

The next step after drilling is the formation of pipes from roofing material. Their diameter should be equal to the diameter of the well, and the length should be three hundred millimeters more than its depth.

The upper part of the pipe is made of a three-layer roofing material, after which it is connected with a metal wire. It will be used as formwork. Next, the pipe is very carefully placed in the drilled well. If a small amount of water is found in the well, you can ignore this, but if it is more than one quarter, then before pouring concrete, it should be pumped out with a pump.

In order to improve the strength of the finished pillars, you will need to prepare a reinforcing cage. You can get by in the most inexpensive and simplest way: for this, three vertical metal rods with a diameter of about seven millimeters are taken, which must be fastened together with a soft ceiling.

After the frame is installed, a concrete mixture is poured into the well. It is poured in layers, which are compacted with a vibrator.

Execution grillage

The grillage is made of a concrete or iron beam, the task of which is to perform the connecting functions of the vertical elements of the building structure.

The execution of the grillage is as follows. A trench is dug between the pillars, its depth should be at least thirty centimeters. The width should be such that the formwork fits into it. Its presence is mandatory, since pouring concrete into the ground is a technological error.

After that, you can pour sand within ten centimeters and lay a roofing material tape. The formwork is installed between the pillars.

The fittings are mounted at the bottom of the well, while it should extend beyond the surface by about three centimeters. In order for the reinforcement not to rust, it must be completely immersed in concrete.

After the concrete has been poured, it needs to be moistened. To do this, it is necessary to water it with water for seven days. This procedure is necessary so that the concrete can gain strength.

Further, when the formwork is removed, it is necessary to remove the sand that was poured under the grillage. The result should be something like a bridge between the pillars. This air gap is necessary for the expansion of the land in winter.

Pile foundation with a monolithic grillage: characteristics, manufacturing and construction instructions

Do you want to build a private house on your site and choose a foundation? This article will tell you how to build a pile foundation with a monolithic grillage.

Hello dear forum users! I decided to turn to you for advice and help, I hope for qualified help from knowledgeable people. My situation is the following.
I made a tape-monolithic one with a grillage for a house measuring 9m by 12m in the summer of 2016. The site is located, as it were, in a lowland, at an angle of about 15 degrees, that is, in front of the house: the road and the field, the site is not even.
The composition of this foundation:
1. Ribbon: The width of the tape along the perimeter and in the middle: ~ 350 mm, under the partitions the width of the tape is ~ 300 mm, reinforcement with bars 12 mm thick is used, reinforcement in the tape is as follows: two bars on top and two on the bottom.
2. : under load-bearing walls, partitions and the entire first floor, they were drilled to a depth of 1.7 m with a diameter of 300 mm in increments of ~1.2 m, reinforcement was applied with three bars 12 mm thick (in some places two).
3. Piles under the tape are tied together.
4. By plinth: The soil was removed by 200 mm only where the tape was, the earth was covered between the tapes (I think there was a delivery, I don’t think that it was left from the tape) - it was tamped (or not, I’m not sure, I think so), a pillow was created with sand-tamped (from the photographs you can see that it’s not very , traces are visible), reinforced bars 12 mm thick are laid on the sand in one row (visibly hanging), tied to the tape, cement mortar grade M300 is poured onto the bars, the thickness of the monolithic slab is 20 cm.
4. Above the ground, the foundation rises by about 75 cm.
5. Pipes are connected to the bathroom / unit and furnace.
It is planned to build a house from:
- two full floors + roof (I think tent), gas block + ventilation gap + brick
- load-bearing walls gas block brand D500, 375mm (Preferred) or 400mm, I haven’t decided to veneer yet, I want a brick (250x120x65), but I want to get recommendations on insulation and cladding from you.
- internal bearing walls D500 300mm
- partitions gas block brand D500 150mm.
- ceiling height 2.8 m.
- I plan to make a wooden floor between the first and second floors, but for better rigidity they say to use a reinforced-monolithic floor, which provides additional sound insulation, linking all the walls of the house (structural rigidity).
- yes, and there is also a vestibule attached after the main foundation, reinforcement was released towards the vestibule and tied together, the base of the vestibule is also a shallow tape with piles, an office is planned on the vestibule at the level of the second floor, with an emphasis on the foundation of the vestibule and all this from the gas block D375+brick
Attached are two layout options:
-with brick D500 400mm (left), without brick 375mm (most likely I will replace it with 400mm for reliability) + foundation drawing
And
- An example of a house is shown in the photo: Example of a house 1
- For the mansard roof variant: Example of a mansard roof.
- Pile foundation example.
- Photos of my foundation under the numbers: from 1, 2, 3.
- Photo Conclusion of communications under the furnace and dignity. node.

I understand that the topic has already been raised on this forum, but this is very important for me, because this year I wanted to start building load-bearing walls, making a roof. Waiting for answers, thanks for your understanding and your opinion

For the construction of modern heavy buildings, the rational choice of the foundation is of paramount importance, so the most common option for unstable soils is a bored foundation with a grillage for a brick house, which can withstand heavy loads.

The bored foundation is a type of pile foundation, and its structure is concrete pillars located in wells. Thus, the supports are located in the thickness of the soil and do not damage the soil.

Basically, bored foundations are used on surfaces with significant height differences, as well as in swampy areas where a dense layer is located at great depths.

For a brick house, a combination of two methods is performed using piles and concrete slabs, which is called a pile foundation with a grillage, which is characterized by a long service life.

Minor disadvantages are the susceptibility of metal piles to corrosion, and for the arrangement of basements it is necessary to carry out additional work, which requires material costs.

Construction of bored piles with grillage

A feature of this type of piles is the method of their installation, which consists in direct installation on the site and pouring them with concrete. Wells are previously dug to a depth below the freezing level of the soil to provide additional strength and stability of the foundation.

Bored piles have a round shape due to the use of a mechanical or hand drill, which makes holes in the ground.

The basis for the future brick house is a grillage - a monolithic concrete frame that connects the supports above the ground. The diameter of the pile base is selected taking into account the characteristics of the soil and the bearing capacity of the walls of the house.

A special extension at the bottom of the support saves concrete and reduces the cost of excavation due to fewer piles.

Advantages of using a pile foundation with a grillage

A bored foundation with a grillage for a brick house has a lot of positive aspects compared to other types of foundations, which include:

• Long operational period;
• Increased reliability and structural strength;
• Ability to build on any type of soil;
• Increased resistance to soil movement;
• High quality at optimum labor input of works.

It is also worth noting that the construction of the base in this way is accompanied by a low level of noise, which allows work to be carried out at any time of the day. Virtually no vibration during piling excavation does not affect buildings and structures located nearby.

The use of piles of different lengths on stable soils can significantly save on consumables during the rapid construction of a brick house.

Stages of construction and technology of work

The technology for erecting a bored foundation with a grillage for a brick house is not technically complicated and is carried out directly at the construction site. The construction process consists of the following main steps:

• Preparatory work on the site;
• Marking the area with a choice of places for drilling wells;
• Waterproofing and reinforcement of holes for supports;
• Installation of piles and pouring them with concrete.

At the initial stage of construction, preparatory activities are carried out, which include clearing the site and removing the topsoil.

Then the choice of the location of future supports is carried out, the distance between which is approximately 2-3 meters.

At the next stage, at the selected elevations, using a mechanical or hand drill, wells are drilled under the supports. The drilling depth is determined taking into account the level of groundwater.

For waterproofing, polyethylene bags or high-strength PVC film are used, and the reinforcing cage ensures the reliability and strength of the piles. The bars of the metal frame should protrude above the ground at a distance of 30-40 cm for the subsequent installation of a grillage on them.

Then the resulting structure is poured with high-strength concrete mortar. After the concrete has hardened, the formwork and grillage are installed in order to connect and tie the piles for better fixation.

Necessary tools and building materials for construction

When building small brick houses, special heavy equipment is not required.

And for large construction, the following equipment is needed:

• Automobile crane;
• Concrete mixer;
• Drilling machine or hammer for wells;
• Dump truck and excavator;
• Drilling tool set;
• Transformers for connecting special equipment.

For a bored foundation with a grillage, the following consumables and building materials are required: reinforced frame, waterproofing materials, pipes for various purposes, concrete mixture.

Watch the video:

For brick houses, this type of foundation is characterized by economy in materials and earthworks, a simple technological process and the versatility of using this type of foundation on almost all types of soil. Proper construction technology guarantees a long service life and rigidity of the entire structure.

With individual development, depending on the weight of the building, the type of construction and the complexity of the soil, three types of foundations are most often used:

And, perhaps, the most versatile and cost-effective from a financial point of view is the last type of foundation. After all, bored piles are the element that can be done on your own, without the involvement of complex equipment.

The main advantages of such a foundation:

• Low cost.
• Can be used on almost any type of soil.
• The shortest construction time.
• Low percentage of involved building resources.
• Absolute reliability.

Drilling and pouring technology

The technology of its device cannot be called too complicated, therefore bored piles are made by hand, which reduces construction costs.

The arrangement of the base begins with drilling wells.

Why use a special drill (manual or mechanized) with a diameter of 20 to 30 cm, depending on the expected load. The depth of the hole should slightly exceed the depth of soil freezing and is determined individually for each climatic zone.

At the next stage, asbestos-cement or thick steel pipes are placed in the well, which in this case act as a formwork.

Pre-prepared pipes are necessarily covered with a layer of mastic waterproofing. Such a procedure is necessary in order to completely eliminate groundwater flooding and freezing of piles with soil during severe frosts during the operation of the foundation.

Further, the pipe is 1/3 filled with concrete, after which a frame is installed in it, which is made of a bundle of steel bars of reinforcement enclosed in a cover made of roofing felt, galvanized steel or PVC film.

The reinforcement does not carry any serious load in this case, but it is necessary as a link between the piles and the grillage, which gives the structure rigidity, makes it more durable and reliable.

Then comes the turn of filling the resulting hole with a liquid mixture consisting of concrete, crushed stone and quartz sand.

The solution is added gradually, in small portions, compacted by bayoneting with a piece of reinforcement or scrap. The whole procedure takes place continuously and is completed in one step. This is followed by the formation of the sole of the pile - a broadened heel.

At the final stage, embedded elements are installed on the tops of the supports, which will be needed during further construction.

Or a grillage is being built that combines all the supports into a single structure, which undoubtedly improves the strength of the foundation. Read more about this design in the article Do-it-yourself pile-strip foundation.

The step by step process will be as follows:

1. External piles
2. Reinforcement grillage
3. Monolithic grillage
4. Internal piles

After pouring, it is necessary to take a break for a few days to allow the solution to finally harden.

Video instruction

Calculation of the number of piles

Bored piles are usually installed along the perimeter of the walls of the structure, and in case of a high load of the building structure on the base, also between them.

The number of piles required is calculated based on the weight of the building and the complexity of its geometric shapes. The strength of the supporting element largely depends on the brand of concrete used to create it.

The bearing capacity of a support is largely determined by its diameter.

The device of a bored foundation with a grillage - reliable simplicity

For example, a pile with a diameter of 15 cm, with a support area of ​​177 cm2, has a bearing capacity of about 1000 kg, and with an increase in diameter to 25 cm, this figure rises to 3000 kg. The cross section of the support also affects the price of the final product, since the consumption of materials depends on it.

Do-it-yourself arrangement of a bored foundation allows you to save about 70% of its total cost, the remaining 30% falls on the cost of building materials (pipes, fittings, concrete, waterproofing and other consumables).

The service life of supports is on average about 100 years. The house on bored piles is distinguished by good thermal conductivity and reliability, therefore it is widely used in low-rise buildings.

See also: Bored foundation with grillage, Do-it-yourself bored foundation

Read also:

What are packaging containers
What is good housing for?
Benefits of Boredom Technology
Implementation rules
Characteristics of work on different floors
How to choose case diameter

Using a pipe with a body, you can not only get a high-quality and durable foundation for your building, but also extract coupons during repairs. Long-range hulled pilot construction technology is commonly used in complex floors, resulting in a significant reduction in the time required to complete the initial phase of construction.

What are packaging containers

The use of long pilots is the most efficient method of organizing funeral foundations.

During the drilling process, drilling is carried out to the desired depth, where the copier is equipped with an extended bottom. It can additionally fill concrete mix, soil and sand.

To achieve this "spread" in the lower segment requires the use of special drilling equipment that manages the rock.

The concrete mixture is then wedged, for which even a directional action that calculates the scale can be used.

To obtain a cylindrical cavity in the soil, various methods are used, which have led to the following classification of copy packaging:

• Burobivnaya.
• Sandy.
• An example of concrete.
• Pneumatic.
• They often fade.
• Vibration rammed.

When choosing a suitable option, the main criterion was always on the ground at the construction site.

Thanks to the advent of modern technology, the same procedure can now be used regardless of soil type.

The effectiveness of the method is checked by experts:

• The walls of the recesses are not strengthened.
• The clay solution is used to strengthen the well.
• We use housing products.

What is good housing for?

With the help of pipe bodies, wells of various functional purposes can be obtained.

They are used in construction, oil production, drinking water production. With the release of this product, foreign and domestic companies are guided by GOST 632-80. Pipe gaskets are equipped with a special shape, where the existing ready-made connection makes the connections more convenient.

In some cases, welding clamps or terminals with special clamps may be used.

For the production of such pipes, various materials are used, in particular, we are talking about asbestos-cement, stainless and plastic products. As for casting iron, wood, and some polymers, there may be limited power household coupons.

All such products have the same goal - to protect the good from the abandonment and flooding of sedimentary and groundwater. Metal pipes for pilots allow you to perform construction work regardless of external conditions. At the same time, they temporarily remain in the ground or are extracted from wells: these products are called "inventory".

Drill holes will require special action or rotation mechanisms.

Pipe linings differ in shape, diameter, ovality, differences, unevenness indicators, which are determined by the following standards:

• For pipes from 33.5 mm to 89 mm - inside 0.3 mm.
• For pipes with a diameter of 108 mm to 146 mm - within 0.5 mm.
• Large-scale pipes allow a defect of more than 0.7 mm.

The casing for asbestos-cement asphalt piles is usually a thick wall: it is the most fragile of all products of this type.

Its popularity explains the availability and availability of products, but inexperienced workers may encounter certain drilling problems. The installation of the casing is characterized by several phases, since each subsequent pipe must be attached to the previous one. Also read: "Pipe bodies and rules for their use."

In addition, after the pilots are installed, they can be removed to the surface or left in the ground. This point should be sure to correct the technical work log and receipt for each pile. The drill must be cleaned of the scattered floor.

A blunt foundation with a throat under a burnt house

This is done with a special drill or Kelly bar equipped with adjustable gripping blades.

Benefits of Boredom Technology

With the help of pipe bodies, we can provide reliable reinforcement of the floor walls inside the wells.

These products include rigidly connected parts. This technology has practical effectiveness not only in the presence of problematic floors, but also in construction in a big city in a limited space.

The following factors directly affect the time and cost of assembly work:

1. In what condition are the drilling mechanisms.
2. Required dimensions.
3. Type of soil at the construction site.

The technology for using long pilots and hulls does not differ significantly in complexity.

If it is necessary to form deep rods, the gradual formation of the drill shaft is used to connect the pipes to each other.

At the same time, the casing products must be firmly fixed during the penetration depth, regardless of the material made. Also read: "Drill Hose Types, Specifications, Usage Characteristics".

Implementation rules

Work order:

• At the prepared site, drilling equipment for well production is installed in accordance with the dimensions specified in the project.
• For plastic and metal pipe bodies, the screw is attached to the pipe. The required level parameters also include project documentation.
• Techniques specific to such pipes (so-called "forward penetrations") are used to connect individual segments to each other.
• Upon completion of the drill string, a soil sample is taken, which, after completion of its work, is taken.
• The terminal shaft is equipped with a cage for pilots.
• A concrete pipe is used for the sequential supply of prepared cement sand mixtures.

  This procedure is called “pilot packing”.

• When extracting sections from a recess, it is important to follow the sequence.

This is a good way to use long pilots and casings:

• This opens up opportunities for building work in the background with existing structures, as there is no shock or vibration during excavation.
• You can work on difficult soils - saturated with water, weak, fragile, sunflower, with fins.
• Complete vertical and high quality drilling operations are guaranteed.
• Drilling mechanisms have high productivity.
• Work can be performed at depth, in conditions of overlapping horizons.
• Peeling is good security.
• Waters are reliably protected from collapse at all stages of technology implementation.
• The drill shaft is protected from ground water.
• Efficient filling of concrete without a door makes it possible to almost completely avoid material losses.
• Calculations during installation are reduced.
• The drill allows you to make holes and extensions, as well as extrude bales and large fractions at break.
• Possibility of continuous monitoring of compliance with design parameters.
• The finished well has the maximum possible throughput.

  This is achieved thanks to the presence of high quality walls.

Housing hoses can also be made of the following types of plastics:

1. LDPE is high density polyethylene.
2. HDPE is low density polyethylene.
3. PNP - low density polyethylene.
4. PVC is polyvinyl chloride.

The wall thickness in these products is usually less than 40 mm. Also read: "How to remove the tube from the ground - ways to remove the body from the wells."

Advantages of plastic cases:

• Good tightness of the joints of certain areas.
• Excellent corrosion resistance.
• The price of plastic pipes is noticeably lower than that of similar metal products.
• Small mass.
• Good tolerance to chemical and other aggressive effects.
• Working with plastic pipes is very fast, which makes it easy to connect parts to each other.

The only weakness of these products is their low power: in order to destroy their integrity, the attack is quite sharp with a sharp object.

Therefore, the use of plastic pipes for the BNS housing should be avoided. The main area of ​​application of this inexpensive and practical product is the regulation of domestic wells for supplying water to private homes.

Characteristics of work on different floors

If there are aggressive waters of natural or industrial origin in the area, it is better to work with asbestos-cement pipes.

Reinforcement of the drill shaft is not performed in cases with swelling and refractory plastics.

Difficult geological conditions allow the use of the pipe body when working with long pilots.

In particular, this applies to areas where landslides and landslides occur: in this case, the pipes of the pipes remain in the ground. If excess wet pressure is present, the channel walls are further strengthened. Also read: HDPE Casing Types - Choose the Right Piping, Insulation and Downhole Installation.

When the work is completed, the pipe parts are disassembled. Sometimes the project requires us to leave them in the ground: this is done to further protect the soil from the concrete from the impact of the soil in areas with geological and seismic activity.

How to choose case diameter

Specialized catalogs contain a list of hole diameters.

There is special code for defining these parameters; they are also described in the technical documentation for outside and inside diameters. This allows very precise adjustment of the pipe to the produced well, for which there are certain international standards. The outside diameter marking can be used with markings 620-2500 mm and inside diameters from 640 to 2580 mm.

To improve watershed performance, buying pipes with a significant diameter is not always a good choice - it still won't be able to top more water than it can get outside the water supply or aquifer laying. When choosing a product with the right diameter, it is important to match the flow characteristics of the well.

When the completion of drilling is completed, it will take three days to drain the earth and drain the water. These compulsory measures are the best way to regulate the required expansion: as a result, the water in the well can move to a larger volume.

For the production of deep holes up to 15 m for drilling pilots with a casing, rented equipment can be used. It consists of a drill, pushers, revolving doors and fittings that fix the pipes. A similar drilling technology is used for laying foundations: the best way is to build walls.

If such events seem difficult to implement independently, they can be limited to just preparing the website and inviting a large team into a specialized team.

Prices for such services may vary, which are affected by a number of factors. The company that does this work usually provides valuation and accounting documents with local rates.

This includes the cost of acquiring and transporting the necessary materials to the workplace.

Installation costs for long pilots include the following items:

• Development of project documentation.
• The material from which the pipes are made.
• The technology used in this case.
• Depth and width of drilling.
• Geological features of the city.
• Order speed requirements.
• Equipment status.
• How many wells are needed.

Each method has its own advantages and disadvantages, which are taken into account when choosing the most optimal option in a particular case.

The specific seal in the housing is very versatile in this regard and is therefore recommended in most cases.

1. Prior to the start of piling, cutting or backfilling of the soil is carried out to the design mark of the grillage and the pile field is laid out.

If the work is carried out using a clay solution, then the quality of its preparation is checked.

2. When installing bored piles, the bottom of the well must be cleared of loosened soil or compacted by tamping. Compaction of non-saturated soils should be carried out by dropping a rammer into the well (with a diameter of 1 m or more - weighing at least 5 tons, with a well diameter of less than 1 m - 3 tons). The compaction of the soil in the bottom of the well must be carried out to a “failure” value not exceeding 2 cm for the last five strokes, while the total amount of “failures” of the rammer must be at least the diameter of the well.

3. The level of the mud solution in the well during its drilling, cleaning and concreting must be at least 0.5 m higher than the groundwater level (or the water horizon in the water area).

4. Upon completion of drilling, it is necessary to check the compliance with the project of the actual dimensions of the wells, the marks of their mouth, the bottom and the location of each well in the plan, and also to establish the conformity of the soil type of the base with the data of engineering and geological surveys (if necessary, with the involvement of a geologist).

5. In flooded sandy, subsidence and other unstable soils, concreting of piles should be carried out no later than 8 hours after the end of drilling, and in stable soils - no later than 24 hours. stop without bringing their bottomhole by 1-2 m to the design level and without drilling widenings.

Do-it-yourself bored foundation

6. Immediately before the underwater placement of the concrete mixture in each well drilled in rocky soil, it is necessary to wash off the drill cuttings from the surface of the face. For flushing, it is necessary to provide water supply under excess pressure of 0.8-1 Pa at a flow rate of 150-300 m3/h.

Flushing should be continued for 5-15 minutes until the remaining sludge disappears (which should be evidenced by the color of the water overflowing over the edge of the casing pipe or branch pipe).

Flushing must be stopped only at the moment when the concrete mix begins to move in the concrete pipe.

7. To control the continuity of the concrete shaft of bored piles, performed by the method of underwater concreting, it is necessary to selectively test samples taken from cores drilled in piles, or to control the continuity by non-destructive methods from one pile for every 100, but not less than two piles per object construction, as well as in all piles, during the installation of which violations of technology were allowed.

8. In the process of installing a camouflage widening of each pile, it is necessary to control the marks of the explosive charge lowered into the bottom and the surface of the concrete mixture in the pipe before and after the explosion.

9. Bored hollow piles should be made of rigid concrete mixtures with a cone draft of 1-3 cm on crushed stone with a fraction of no more than 20 mm.

The inner surface of the shaft of each bored hollow pile shall be subjected to visual inspection. If concrete fallouts with an area of ​​more than 100 cm2 are detected or the working reinforcement is exposed, the pile cavity must be filled with a concrete mixture with a cone draft of 18-20 cm to a height exceeding the mark of the detected defect by 1 m.

10. Drilling a well when installing bored piles in unstable watered soils should be carried out with flushing of wells with clay (bentonite) solution or under the protection of casing pipes. The density of the clay (bentonite) solution should be taken equal to 1.05-1.15 g / cc.

The solutions used for the manufacture of bored piles should have a density in the range of 1.73-1.75 g / cubic cm, mobility along the AzNII cone of at least 17 cm and water separation of no more than 2%. The composition of solutions for bored injection piles should be specified in the project.

Filling boreholes of borehole piles with hardening (cement or other) mortars should be carried out through a drilling string or an injector pipe from the bottom of the well from the bottom up until the clay mud is completely displaced and a clean cement mortar appears at the wellhead.

11. The laying of the concrete mixture in the well should be carried out without interruptions, exceeding the period of the beginning of the setting of the mixture. When concreting, it is necessary to ensure the laying of high-quality concrete throughout the depth of the well, including at the head of the pile. In the process of concreting bored piles, a log of concrete work should be kept. Control concrete samples should be taken in the amount of 3 pcs.

for every 50 cu. m. of laid concrete mix. The production and storage of control concrete samples should be carried out under conditions similar to those in which concreting and hardening of piles takes place.

12. In the process of concreting piles, the following are subject to control:

— quality and temperature (in winter) of the concrete mix;

- the intensity of laying the concrete mix;

– technology of filling the well with concrete mix;

- the volume of concrete laid in the well;

- the time of the beginning and end of concreting, as well as the time of forced breaks.

13. Quality assessment and acceptance of foundations from stuffed and bored piles is performed on the basis of the following documents:

— project of pile foundations;

- acts of acceptance of materials used for the manufacture of piles;

- acts of laboratory tests of control concrete cubes;

- certificates of control check of the quality of laying the concrete mixture in the well;

— acts of control of manufactured piles (core sampling or non-destructive testing);

- an act of conclusion on the conducted static tests of experimental piles;

— plan for the location of piles with reference to the center axes;

— an executive scheme for the location of the pile axes, indicating deviations from the design position in the plan and the results of leveling the pile heads;

- acts for hidden work

— magazines for the manufacture of piles.

When accepting finished piles, it is necessary to check the compliance of the work performed in kind with the requirements of the project. Acceptance is formalized by an act in which all identified defects must be noted and ways to eliminate them are provided.

Source of information: All-Russian public fund "CENTER FOR CONSTRUCTION QUALITY", St. Petersburg

Bored piles are a special method that is based on drilling a well and then pouring it with high-quality concrete. The process of effective concreting is carried out using reliable reinforcement made of metal. Similar structures are being built for the most part in the field of suburban construction. in direct dependence on the type of soil, a solid formwork may or may not be installed. These are stable soils, there is no risk of wall shedding during operation.

Features of the use of bored piles

Well-made bored piles are used in urban and suburban construction.

Such structures are simply indispensable in situations where other methods of driving onto adjacent buildings have a special dynamic effect. Bored piles are used in the following cases:

• In heavily wetlands, on soft soils, if the hard layers are very deep;
• In the process of building houses on fairly steep terrain;
• In the construction of complex and heavy industrial buildings;
• In places where it is not economically feasible to build a solid foundation, in the construction of wooden and frame objects.

The scope of this service is quite wide.

This kind of work is carried out exclusively by professionals.

The main technologies of the device of piles

High-profile specialists have all the necessary equipment for carrying out the installation of bored piles.

These processes are carried out using the following modern technologies:

CFA Technology

CFA - piles using a continuous hollow auger. It is applied in dense on structure and water-saturated soils.

DDS technology

DDS - arrangement of piles without excavation.

Grillage on bored piles

The soil is displaced by special drilling tools. The technique is characterized by the complete absence of noise and vibration, which is ideal for buildings in the city.

CAP technology

CAP - piles are arranged using a special casing pipe.

CSP technology

CSP - secant piles, ideal for soil with relatively weak bearing capacity.

Double Rotary Technology

Double Rotary is a combination of two technologies - CFA and casing technique.

The technology makes it possible to build a foundation without a special bentonite mortar. Ideal for waterlogged and weak soils.

Kelly Bar Technology

Kelly bars are bored piles that are installed using a telescopic Kelly bar.

Suitable for different types of soil, as there are no vibration effects on the soil.

Fundex Technology

Fundex – high-quality compaction piles, which are installed using a special casing pipe equipped with a lost tip.

Professionals choose technologies based on the characteristics of the soil, on the surrounding conditions and on the technique that can be used in a particular case.

Regardless of the chosen method, at each stage, a thorough control is carried out on the overall quality of the work. in this way, various problems in the operation of piles can be avoided.

The main advantages of bored piles

Regardless of the type of technology for arranging piles, such structures are characterized by a large number of advantages.

Among them, one can note the low noise, the minimum amount of excavation, the complete absence of the need to purchase, transport and store a large amount of finished piles. Such piles can be arranged in different lengths, diameters and at different elevations. If the calculation of bored piles is carried out, the time period and the total cost of construction are significantly reduced.

Cost of work

Do-it-yourself base with lifts on swinging piles

One of the main activities of PSK "Funds and Funds" is the installation of long pilots.

Let's see how to choose for them and what is the technological regulation of a particular bureaucracy.

The use and characteristics of boring foundations

Based on boredom, they are indispensable in urban environments, where the classic peeling method is prohibited by vibrations on the ground.

The use of equidae is possible on all floors, with the exception of stone and rough piles. The installation sequence is as follows:

• Drilling a well with a diameter and depth of design;
• reinforcement;
• concreting.

In many cases (for example, when drilling with hollow screws), the sequence is reversed: first pour, then immerse the cage. The bars protrude above the level of the concrete: these ends are later used to connect the pilots to the mesh.

During continuous drilling, light earth, together with a submersible body, forms the wall of the wellbore and serves as guides in the design of the pilots.

When filling the hole with mortar, remove the hose (not always).

Another way to reinforce a wall is to wash with clay mortar: it removes the core from the well and strengthens the walls. The method is suitable for thin fingers of medium stability.

The capacity of each element is determined based on the following indicators:

• hoof diameter;
• immersion depth;
• soil characteristics;
• concrete brand;
• Type of reinforcing and reinforcing characteristics.

What kind of concrete is used in boredom?

Do you need a foundation for boredom?

Work experience - more than 10 years.

We include the installation of foundations of all types and recommend the most suitable option depending on the construction conditions.

And even in the shortest possible time, we will collect the project and provide you with a ready estimate.

Concrete class for boredom - SNIP

Edition 2.02.03-85 SNiP is the main document that regulates the concreting of long pilots. GOST for specific classes:

• 19804.2-79;
• 10060.0-95;
• 12730.0-78;
• 12730.4-78;
• 12730.5-84.

In accordance with the standards for various structures, concrete is selected as follows:

• M100-150 - preparatory work and installation of non-structural structures;
• 200-250 - belts, reinforced concrete belts, grill;
• 300-350 - beams, facades, ceilings, stairs, boredom.

Composition of concrete for filled pilots:

• 25% of the ruins with capacity designed to load 50-60 megapascals;
• 25% sand;
• cement - 340 kilograms per cubic meter of the mixture.

Depending on the operating conditions, mixtures can be added to the mixture.

Consumption of concrete in the construction of long pilots

A bunch of white bore pilots can be defined according to the calculated basic properties of the pilots - load capacity, diving depth, cross section, number step.

Obviously, the greater the load from the structure, the lower the speed and the more important other parameters. On a grounded site for concrete reinforced concrete houses, less material will be required than in the basement for the construction of heavy concrete.

To determine the amount of concrete, you must multiply the number of one pilot according to their number. Portable piles - the capacity of the cylinder, the height of which is equal to the depth of immersion, and the diameter of the place is equal to the diameter of the velvet / casing (if not covered).

According to building codes, the consumption is 1.02 cubic meters. M per 1 cubic meter of construction.

In addition to cut pipes, we also manufacture drilling, injection and drilling piles.

All work is turnkey!

At the request of the client, we will complete all the work on the key, from geological surveys to ignition.

Checking the continuity of specific pilots

The actual carrying capacity of the concrete substrate corresponds to the design only if the concrete is solid, there are no voids.

According to international standards, using the first method, 20% of the pilots are subject to partial destruction, which is uneconomical.

Main incompatible testing technologies:

• surface testing (PET);
• cross-monitoring (CHUM).

In the first case, there is a shock pulse for each pile, the ultrasonic sensor of the tester determines the unblocked waves, the device interprets the information graphically.

In our articles, we have repeatedly talked about various foundation designs, how they are arranged, for which buildings they are more suitable, how to independently calculate the foundation. We also wrote that one of the most economical bases for light frame houses, for houses made of aerated concrete or logs, is a columnar or, as it is often called, a pile foundation.

In this article, we will tell you about how to make a monolithic concrete grillage for a pile foundation how to properly reinforce and insulate it.

By its design, a grillage is a concrete, metal or wooden strip, which is attached to the top of a columnar foundation or foundation on screw piles. The main task of the grillage is to redistribute the load from the entire structure to the piles, which in turn transfer it to the ground.

For example, during the construction of a log house, its lower logs, which lie on the pillars, perform the function of a grillage. In frame housing construction, the lower trim of the house also performs a similar function.

We will not consider wooden or metal types of grillage, they are made quite simply, but a monolithic concrete grillage requires a more professional approach.

By this time, piles should be installed on the site. It does not matter what they will be - lined with bricks or poured with concrete.

For the formation of formwork, edged boards with a thickness of 2.5 cm or more, chipboard, OSB, plywood and any similar material are suitable.

Once the entire volume of material has been prepared, you can begin to collect the formwork. It is important to know that the height of the grillage must be at least 30 cm, and the width at the base of the tape is 10 cm more than the width of the pile.

In shape, the grillage is made in the form of a rectangle or in the form of an inverted trapezoid. It can also be made stepped, while the top should be a little wider.

Consider in stages one of the most popular formwork options.

1. The first thing to do is mark the edges of the future formwork and hammer wooden bars with a section of 5x5 cm along this line every 50-90 cm. The bars should be placed strictly vertically.

2. The bars driven into the ground must be securely connected at the top using the same bars. You can use wire for this.

Further, with the help of self-tapping screws, the lower bar is screwed. For this, boards 3-4 cm thick are suitable. The lower part of the entire formwork will lie on these planks.
3. The next step is to install the boards. First, the boards are laid horizontally. Here you need to carefully cut the holes for the piles. The tighter the formwork is pressed against the posts, the less concrete will flow out.

After that, the boards are placed vertically. In order for them to hold securely, they are nailed to vertically standing bars, which were driven in at the first stage.
4. As soon as the formwork is assembled, a plastic film is spread over the entire inner surface. It prevents the leakage of cement laitance, which is necessary for the proper maturation of concrete. The film can be shot with a stapler so that it does not fall.

This completes the assembly of the formwork frame.

If you are not sure about the reliability of the design, then you can add additional stiffeners and various stops.

Reinforcement grillage

Concrete is a very strong material, but, as you know, it works well in compression, and bursts when stretched and bent. To eliminate this shortcoming, it is reinforced. Reinforcement, on the other hand, behaves well in tension. Thus, these two materials being together form a strong and reliable construction.

The reinforcement of the grillage consists of several stages.

1. First, bars are laid on the bottom of the formwork. Their thickness should be the same. Bars 3-5 cm thick will do. The width is not important here.

What is it for?

According to the rules, the reinforcement should be no closer than 3 cm from the outer concrete surface, i.e. it must be completely sunk into the concrete. Thus, the bars, in this case, are stacked for convenience.

2. Laying the bottom row of longitudinal reinforcement.

To do this, use ribbed reinforcement with a diameter of 10 mm or 12 mm, which is placed on the bars. How to calculate their number, we will consider in the example below.

3. At this stage, it is necessary to tie the longitudinal reinforcement together so that the distance between the individual rods is the same.

For the bundle, smooth rods 6-8 mm thick are used because they are cheaper and do not perform any other function as giving geometry to the frame.

Thus, the bottom row of the reinforcing cage is fully assembled and you can start assembling the top row.

4. Assembling the top row. We will look at one of the ways how you can assemble the top row.

As we wrote above, the bars driven into the ground were connected from above with a bar. Reinforcing bars are hung on these strips using wire. The height at which the reinforcement should hang depends on the height of the grillage. At the same time, do not forget that the reinforcement in concrete should be located no closer than 3 cm from the edge.

Thus, the armature is suspended.

5.Now you need to tie the bars of the top row together. This is done in the same way as the bottom row.

6. It turned out two rows: upper and lower. They are also tied together with smooth rods of 6-8 mm.

7. As a result, a reinforced rectangular frame should be obtained. Since the upper bars were hung on a wire and both rows were interconnected, the wooden blocks that were laid at the first stage can be removed.

It turns out that the entire frame weighs on the wires. At this stage, the reinforcement can be considered complete.

Calculation of the number of reinforcing bars

According to the general rules, the cross-sectional area of ​​the longitudinal reinforcement should be at least 0.1% of the cross-sectional area of ​​the grillage.

As an example, let's take a grillage with a section of 40x40 cm. Let's translate centimeters into millimeters and calculate the area. It will be 160000 mm 2. Accordingly, the total cross-sectional area of ​​\u200b\u200bthe reinforcement is 160 mm 2.

We also know that a suitable rod diameter is 10 mm or 12 mm, while their number in the upper and lower rows should be the same.

The area of ​​a round bar is found by the well-known formula S=πd 2 /4. Where d is the reinforcement diameter.

We get: S 10 \u003d 78.5 mm 2, S 12 \u003d 113 mm 2.

By dividing the total cross-sectional area of ​​​​all the rods by the area of ​​\u200b\u200bone rod, we get their required number.

Rounding the figures obtained, we obtain that the number of reinforcement n 10 \u003d 2 pcs and n 12 \u003d 1 pc.

According to technology, the installation of one reinforcing bar in a row with a width of more than 15 cm is prohibited. It turns out that with such a grillage, there should be 2 bars in a row. Thus, their total number should be 4 pieces.

Grade and composition of concrete for grillage

We will not write much about this. As a rule, at the stage of pouring concrete, everyone is interested in the question of what brand of concrete to use for the grillage and how to prepare it yourself.

For the grillage, concrete grades M300 and M350 are used. If you prepare concrete on your own, then you can find the necessary proportions on our website in the article "Grade and composition of concrete".

It is also worth saying that when pouring concrete, it must be bayoneted, i.e. expel air that gets stuck in the thickness of the concrete.

To do this, use a special vibrator, which can be rented. You can also use a bar of reinforcement and a bayonet to expel air.

This must be done very carefully, otherwise, after solidification, in places where air voids form, the grillage will be weakened.

Grill insulation

The pile-grillage foundation, like any other, needs to be insulated. The exceptions are cottages and houses intended for living in the warm season.

A concrete grillage will serve as a cold bridge, which can negate all the insulation of the house.

The insulation scheme is quite simple and can be produced after the construction of the house. To do this, it is enough to fix an ordinary white foam plastic on the outer surface of the grillage or use a more expensive, but also better extruded polystyrene foam.

The use of soft insulation materials such as stone wool or glass wool is undesirable. They absorb moisture well and as a result lose their thermal insulation properties. Foam plastics do not have this disadvantage.

As a rule, foam plastic 5-10 cm thick is used to insulate the grillage. This is quite enough.

They fix it with special dowels, and the joints are foamed.

Many make a mistake at the installation stage - they put the foam on the ground and then fix it. The error in this case is that the foam should be at a height of 5-10 cm from the ground.

The fact is that frost heaving forces act on the ground, which raise or lower it. What kind of forces we wrote in the article (link). So, if the foam is located on the ground, then when the soil rises, it will simply be torn off the walls or it will break.

Many are afraid that if the foam is not pressed tightly to the surface of the earth, the floors of the first floor will be cold. This is wrong. In order for the floor to be warm, it is insulated. On this topic on our website there are a couple of articles "Floor on the ground."

The surface of the foam is often finished with plinth panels imitating brick laying. Extruded polystyrene foam can be plastered. But these are topics for another article. It is important to understand that the grillage must be insulated. This will save money on heating and make the temperature in the house more comfortable.

The difference between pile-grillage and strip foundations

Many people mistakenly believe that a pile foundation with a grillage and a strip foundation are one and the same. In fact, these are two completely different reasons.

The strip foundation is located directly on the ground and transfers the load from the building over the entire area.

Rostverk has a different function. It redistributes the weight of the building to the pillars, which in turn transfer the load to the ground.

An important difference is that the grillage should not come into contact with the ground, otherwise the frost heaving forces, which we talked about a little higher, can break it or pull the piles out of the ground along with it.

In the presence of unstable soils with high humidity or complex terrain, the only way out is to install pile foundations. The main advantage of such structures is the reliability of fastening even in soft soils due to the deepening of the support to a sufficiently large depth. Such devices are more reliable and durable, do not require a large consumption of concrete, but their construction is a rather laborious process.

With the correct calculation of the number of piles and the depth of their immersion, the foundation will not be exposed to moisture and freeze, therefore, in some cases, it may be preferable to tape. In places of small relief differences, when leveling the slope is unprofitable, it is possible to use a combination of conventional strip and pile foundations.

1. Types of foundations with grillage

A grillage is called the upper part of the foundation, which unites the pile heads and serves as a support for the future building. The connection of piles and grillage can be carried out by welding (in the case of using reinforced concrete structures) or by pouring concrete.

According to the installation method, the grillage is divided into:

• tape - only neighboring piles are connected;
• made in the form of a plate - each head is connected.

According to the type of materials, the grillage can be made:

• from concrete with the laying of reinforcement - piles are installed under the bearing walls, shallow trenches are dug to the depth and width of the grillage;
• suspended concrete - similar to the previous version, however, its peculiarity is that the concrete tape does not come into contact with the ground, while the compensation gap device ensures that the supports do not break when the ground oscillates;
• reinforced concrete - from a wide metal channel or I-beam, and a channel 30 is installed under the bearing walls, the remaining supports are connected by a channel 16-20;
• from wood - used less often;
• combined method - using both metal bearing elements and concrete.

2. Calculation of the distance between piles and the depth of their immersion in the pile foundation

The depth of piles is calculated based on the type and complexity of the soil. The lower part of the support should be 20-30 cm below the standard freezing depth of a certain type of soil in the region of residence. For example, the freezing depth for St. Petersburg, according to geologists, for clays and loams is 1.4 m. For the construction of the foundation, piles of at least 140 + 20 = 160 cm in size will be required. 10-20%.

To determine the required number of piles and the distance between them, SNiP No. 2.02.03-85 and GOST 27751 are used, which list the main requirements for the construction of pile foundations. The following characteristics are taken into account:

• strength of pile and grillage material;
• the bearing capacity of the soil (in this case, compaction is taken into account when installing the support);
• in the presence of significant differences in relief - the bearing capacity of the base (heel) of the support;
• degree of pile shrinkage under vertical load.

2.1. Procedure for making calculations

1. To start the calculations, you need to determine the size of the total load on the future foundation, that is, find out the weight of the building. This takes into account not only the mass of the walls, but also the floor, ceilings between floors, the weight of the roof, internal and facade cladding.
2. Payload (weight of furniture, household appliances and people) - if 200 kg / sq. m, then in the construction of residential buildings, 150 kg / sq. m.
3. The snow load in winter is added to the resulting weight amount. The pressure of snow masses for most regions of the Russian Federation is 180 kg / sq. m.
4. The sum of all three of the above loads is multiplied by a safety factor of 1.1 (in some cases a factor of 1.2 may be used).

When purchasing ready-made screw piles, one should take an interest not only in their height, but also in the ability to withstand a certain type of load. So, VSK screw supports, having a size of 86x250x2500, will have a maximum screw depth of 1700 mm, while one pile is able to withstand a load of 2000 kg. Methods for calculating the load for bored piles are more complex. Perhaps, for the calculations you will need the help of specialists. More details about the installation of concrete piles can be found in SNiP No. 2.02.03-85. A good reference book can be the book "Universal Foundation" by R.N. Yakovlev, which provides detailed calculation methods.

2.2.

Construction of a pile foundation with a monolithic grillage

An example of calculating a pile foundation with a grillage

Screw piles are used for the construction of light country houses, while in the construction of heavy cottages, more massive bored piles are used that can withstand a serious load.

In this example, for simplicity, the calculations are carried out on screw supports. It should be noted that if for such small piles the lateral friction is not taken into account in the calculations, then in the case of the construction of heavy buildings on bored piles, the lateral friction forces affecting the pile are also taken into account.

Calculation of the total number of piles and the step of their installation for a one-story house measuring 6 × 6 m:

1. Determine the total weight of consumables.

   Let's say the total weight of the beam, roof and cladding of the house, taking into account the snow load, will be 27526 kg.

2. The payload size is 6 × 6 × 150 = 5400 kg (the payload given in paragraph 2.1 is multiplied by the length and width of the future house).
3. The snow load is 180 × 6 × 6 = 6480 kg.
4. Thus, the total mass of the load on the foundation will be 27526 + 5400 + 6480 = 39406 kg.
5. We multiply the resulting weight by the reliability factor 39406 × 1.1 = 43346.6 kg.
6. Let's say we plan to install screw supports 86x250x2500 VSK. To calculate their number, the resulting amount of the total load of 43346.6 kg should be divided by the load per pile 43346.6/2000 = 21.673. We round the resulting number to 22. Thus, to build a house measuring 6 × 6 m, we need 22 piles.
7. To install 22 supports, the installation step will be 1.2 meters. For sex logs, 2 more piles should be added, which will be located inside the house.

3. Do-it-yourself foundation with a grillage

In the construction of private houses, bored machines are used only in cases where the soil is not dense enough and in order to find a denser area, it is necessary to go deep into the earth to a sufficiently large depth. If the thickness of the soft soil is large enough, it is possible to use composite piles from separate detachable sections.

In most cases, when building a private house, it is enough to install a bored pile. To do this, in the ground, a hole of the required depth is made in the ground using a garden or hand drill.

3.1. Marking and drilling of wells for piles.

After clearing and leveling the site, markings are made at the site of the future foundation: by pulling the threads, the location of the internal and external boundaries of the grillage is determined on the ground. The supports to which the stretched marking rope is attached, it is better to bring them outside the perimeter of the future foundation, so that the corners of the future foundation are formed at the intersection of the stretched threads.

Further, the place of each support is marked with reinforcement or wooden stakes. You can simply make a small hole in the place of the future pile and spill it with water: a kind of "marker". Piles must be installed at all four corners of the future foundation, and then from each corner the required distance to the next is marked, while the supports must be installed at the intersection of the walls.

Too often spaced supports will significantly increase the material costs of their construction. Their rare location can lead to significant deformation of the grillage, and then to the appearance of cracks in the bearing walls.

After the completion of the marking of future piles, the construction thread, which served as the marking of the boundaries of the future grillage, is removed from the supports, and drilling of wells for the piles is carried out.

3.2. Filling wells. Foundation pile reinforcement

Before pouring concrete, each of the wells is reinforced. The reinforcement is laid out longitudinally along the entire length of the pile. For each of the pillar supports, 4-6 rods with a diameter of 12-10 mm are sufficient. To give stability, each of the reinforcements is pre-welded together with a wire. It turns out a kind of frame (mortgage), which is inserted into the prepared well. The reinforcement must necessarily protrude above the pile - its length must be such that adhesion to the grillage is sufficient. The distance from the walls of the well (in the case of formwork installation - from the formwork walls) to the rod is at least 5 cm.

To avoid the appearance of air pockets, concreting should be carried out in layers of 25-30 cm. Each subsequent layer is tightly compacted with a spade-bayonet or a vibrator. To prevent seams at the joints, each subsequent layer is poured before the previous one dries.

3.3. Reinforcement of the pile foundation grillage

On top of each pillar, before installing the grillage, waterproofing is made of tarred roofing material. Instead of resin, it is possible to use hydrostekloizol.

Further, the marking thread is again pulled over the abandoned supports, and within the indicated boundaries, a pillow of crushed stone and sand is laid under the future grillage, which is spilled with water and compacted. To ensure that water does not go into the ground when pouring concrete, polyethylene or roofing material is laid.

The reinforcement of the grillage takes place before the installation of the formwork.

After the completion of the binding of the reinforcement, the marking thread is pulled again and the formwork is installed along it.

The pouring of a monolithic grillage is carried out in the same way as when pouring a strip foundation.

To equip a “hanging” foundation, a layer of sand is preliminarily laid under it, which is removed as the structure dries. You can replace the sand with a wooden box in the shape of the letter "P", which is installed on a layer of bricks. After 3 days, the box and bricks are removed.

Alexander Kiyaev Date: 2015-02-11

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Monolithic piles

Since the time of the Soviet Union, pile foundations have been used in the construction industry as an alternative to powerful volumetric reinforced concrete structures for the construction of buildings on moving soils and unstable soils. Also, the use of piles is typical for soils subject to freezing more than 1.5 meters.

In such cases, a pile foundation with a monolithic grillage is the most effective, in contrast to the tape type of foundation for construction. And also the use of this type of foundation is quite successful for all types of soil and construction conditions.

Do-it-yourself pile-grillage foundation construction technology

A monolithic grillage, applicable in this design as a connecting element, is necessary to evenly distribute the weight load of the building structure between the installed foundation piles for construction.

Concrete for pouring piles

For the manufacture of concrete for pouring monolithic piles and grillage, there are mandatory requirements, and the main one is strength. The brand of the mixture obtained must be at least M - 200 for a one-story and two-story house, and in cases of unstable soils or the expected impact of aggressive groundwater, building codes require the use of stronger concrete grades M - 250 or M - 300.

The composition of the mixture also includes pure river sand filled with crushed stone with a fraction of 20 - 40 mm. It is strictly forbidden to use bricks, residues of gypsum structures and coal burnout products as a filler.

Any qualified specialist in the construction industry will tell you which cement is best for the foundation, and what materials you need to purchase to get a first-class mixture.

Types of grillages on piles

Structurally, the piles, as already mentioned, are combined on top with a grillage, which also contributes to leveling the settlement of the piles. According to the type of materials, grillages are divided into wooden, concrete and reinforced concrete.

In modern use, wooden grillages are strapping crowns for garden houses made without making a base (colloquially, houses "on chicken legs").

Concrete grillages or pillows are used on any piles. When a solid reinforced concrete slab is supported on piles, such a cushion can be arranged with a minimum thickness sufficient to cover the heads of the piles and form a flat surface for laying out the structure.

Concrete pads do not provide reliable fastening of piles working in tension. In this case, the grillages are made of reinforced concrete, and their reinforcement is securely connected to the reinforcement of the piles.

Videos monolithic foundation on piles

Video clip describing the features and benefits of a monolithic pile foundation.

Production of a monolithic foundation

A pile foundation is a type of foundation in which the loads from a built house or cottage are transferred to the soil with the help of piles arranged using bored technology. First, a well is drilled with a diameter corresponding to the pile diameter (calculation of the bearing capacity along the pile surface), then it is reinforced with steel bars of a periodic section and then concreted with vibration to the entire depth of the pile.

The piles themselves come with a widening of the heel for frontal soil resistance (TISE technology), and without broadening, they work on friction only along the lateral surface. The vertical and horizontal loads from the structure are transferred to the pile itself with the help of a grillage, which is a monolithic concrete belt connecting all the piles together. The cross section of the grillage is selected when collecting and calculating temporary and permanent loads from walls and roofs.

It is quite easy to make a pile foundation for a frame house with your own hands. The main required structure is a field of piles, which can be made by pouring concrete into drilled wells or hammering finished reinforced concrete structures using specialized equipment.

The construction process can be divided into several stages:

- production of drawings, taking into account the calculations of the project of load-bearing walls and the corresponding markings on the ground;

– drilling of pits for the manufacture of piles, followed by the manufacture of a reinforced concrete monolithic structure (or driving of piles made in the factory using specialized equipment - a pile hammer);

– production of formwork for pouring the grillage and the upper parts of the piles protruding above the level of the site relief.

In the case of the manufacture of a recessed grillage, the manufacture of a trench for pouring a monolithic structure;

- pouring concrete structures of piles and grillage;

— technological curing of concrete hardening and dismantling of the formwork.

A monolithic grillage is poured, as a rule, into a wooden formwork. Before starting concreting, it is necessary to pump out groundwater from the pit. The concrete mixture is laid evenly over the entire area of ​​the grillage in horizontal layers.

Based on site materials: http://prosvai.com

The foundation is tape. How to do?

A strip foundation is a reinforced concrete structure consisting of a reinforcing cage filled with concrete. As a rule, this is ready-mixed concrete, starting from grade 250. By its appearance, the strip foundation is a closed contour in the form of a strip of reinforced concrete that runs under all the bearing walls of the building. This allows you to distribute the load along the entire perimeter of the foundation and prevent the forces of buckling of the soil and subsidence of the building.

Differences between a strip foundation and a monolithic one.

The strip foundation is the most common type of foundation in the construction of country houses and summer cottages. This is due to the fact that the strip foundation can be used for the construction of monolithic, brick, stone, concrete, frame and wooden houses and is able to carry rather big loads. If we compare between types of reinforced concrete foundations, then, in principle, there are two main types: strip foundation and monolithic foundation, which differ significantly from each other in the payload area. A monolithic foundation has a much larger working area compared to a strip foundation, which allows it to withstand heavy loads.

Pile foundation with a monolithic grillage - reinforcement of the grillage of the pile foundation of the house

At the same time, the construction of a monolithic foundation requires much more building materials and work, which significantly increases its cost. Ultimately, this determines the popularity of the strip foundation over the monolithic one.

Tape, as well as a monolithic foundation, implies the possibility of constructing a basement, or basement floor of a building. In the case when the basement is planned, the area of ​​soil limited between the walls of the foundation is subjected to the removal of the upper layers of the soil. In the case when the basement or basement is not planned, then the soil under the house can be left.

The width of the strip foundation cannot be less than the width of the load-bearing walls of the house, and as a rule, it is usually at least 10 cm wider. To avoid transverse deformation of the foundation under the influence of soil buckling forces, the height of the strip foundation should be at least twice as wide as its width. The cross section of the strip foundation can be made in the form of a rectangle, or in the form of a trapezoid diverging towards the base. In the second case, the foundation will be more stable and durable.

Do-it-yourself strip foundation.

Reinforcement of the strip foundation is carried out by two types of reinforcement: with a variable cross section (ribbed), and smooth reinforcement. Since it is quite easy to avoid transverse deformation in a strip foundation, for this it is necessary to make the height of the foundation at least twice as large as its width, then the transverse reinforcement in the foundation frame can be used smooth. And the entire load will be borne by longitudinal reinforcement, which must be ribbed, because this type of reinforcement provides better adhesion of concrete to metal. When reinforcing a strip foundation, special attention should be paid to its corners, because they are a kind of “weak” link in this type of foundation, and the reinforcement of the corner endings must be carried out with great care.

The strip foundation, according to the method of its construction, can be monolithic or prefabricated. In the first case, this is a reinforcing cage filled with concrete mortar, in the second case, these are reinforced concrete blocks connected by cement mortar using reinforcement.

According to the depth of laying, the strip foundation, as well as monolithic, can be deep and shallow. The depth of the foundation depends on the design loads on it. For example, for a wooden or frame house, a shallow depth of laying will be sufficient, and for heavier structures, a deep one.

The basis for laying the strip foundation is building sand and granite crushed stone. Further, this sand and gravel cushion is covered with waterproofing on top to prevent the foundation from being washed away by groundwater.

It is difficult for a non-specialist to figure out which foundation to choose for a house. Traditional tape and slab lay far from all cases - there are a number of restrictions. In addition, they are quite expensive, which is not always economically justified.

A pile foundation with a grillage will require less investment, therefore, if conditions permit, it is more profitable to use it.

It seems that this is a house "on legs" Source sampochinil.ru

What is a pile foundation grillage type

Such a foundation is a structure of piles buried in the ground below the freezing depth of the soil, and connected at the top with a metal or concrete tape (grillage). The supports can be combined with one common slab, located at ground level or slightly higher. The structure, built according to all the rules, is reliable and has a long service life - several decades.

Source domsdelat.ru

Here you can clearly see what a foundation grillage is - this is the entire upper part of any pile foundation, which is also called the “head”. The task of the grillage is to evenly distribute the load from the load-bearing structural elements on the piles and, accordingly, on the ground.

There are several types of grillage:

• Made. It consists of separate elements, which are a structure of three piles reinforced with a welded frame. To install them, you need a crane.

Source orchardo.ru

• Monolithic reinforced concrete. Represents a solid plate or tape. It is poured directly on the construction site.

Source 24stroim-dom.by

• Prefabricated monolithic. An intermediate version made from prefabricated parts, which, in turn, are assembled at the factory, and are already embedded in place by means of locks and keyed connections.

Advantages and disadvantages of a pile-grillage foundation

Each of the listed types of foundation has advantages and disadvantages, which are taken into account in the design in order to prevent overspending of materials, deformations and cracks in the supporting structures. Among the most common types of foundation, designers have a choice between strip, slab, pile-grillage and pile. If we compare the pros and cons of a pile-grillage foundation with other types of foundations, then the SRF wins in many ways.

In fact, the advantages of a pile grillage foundation far outweigh the disadvantages. Source lowcarb-ernaehrung.info

The properties of the foundation with grillage determine the following advantages of its use:

• applicable to any soil, including mobile and unstable, water-saturated or peaty;
• convenient when building a house in an area with uneven terrain (for example, on a slope);
• does not require a large consumption of materials;
• has a significant service life;
• installation is slightly dependent on weather conditions - work is allowed at air temperatures down to -10 ° C;
• is stable and has a good bearing capacity.

On water-saturated soils, the construction of a foundation requires special skill and accurate calculations. Source termeszetvedelem.hu

• there are limitations related to the bearing capacity: the foundation is used only for one- and two-story buildings;
• the construction of a basement or basement is possible, but is associated with complex and costly design decisions;
• installation requires high precision, so it is strongly recommended to entrust it to specialists;
• installation work involves the use of special equipment.

Types of pile-grillage foundations according to the method of immersion in the ground

• Zabivnaya. The supports are driven into the ground using construction equipment.
• Printed. It involves drilling wells, which are subsequently poured with concrete.
• Screw. It is a method of screwing piles with the help of special equipment.

A special expense item is the use of special equipment Source blog-potolok.ru

On our website you can find contacts of construction companies that offer foundation design and repair services. You can directly communicate with representatives by visiting the exhibition of houses "Low-Rise Country".

Types of piles used

Depending on the method of immersion, piles are selected:

• Drop-in. For them, wells are prepared in advance, with a depth of 1/3 of the height of the pile. For installation, special construction equipment is used: a pressing machine, a vibratory hammer, a vibratory pile driver. Wooden, steel, reinforced concrete and hollow supports are used as driven ones.

Reinforced concrete piles: if the installation technology is followed, the supports will last for many decades Source block-gbi.ru

• Bored. Formwork and reinforcement are placed in the well for strength, then poured with concrete.
• Drilling. Wells are drilled in advance, in which reinforced concrete supports are then installed.
• Screw. They are hollow pipes, in the lower part of which there are blades and a pointed tip. The supports are screwed into the ground using special equipment.

Source stroy-dom-pravilno.ru

Piles can have a rectangular or round section. As a material for them, concrete, reinforced concrete, steel of various grades, wood, mainly coniferous species, are used. Of the tree species, larch is considered the most suitable, containing a large amount of resins that protect piles from decay.

Driven metal piles are one of the cheapest and most durable Source blog-potolok.ru

Piles advantages:

• relative cheapness;
• low installation time;
• independence from the level of groundwater;
• reliability (subject to the installation technology).

Screw piles are used even in permafrost conditions Source museblog.ru

All of the above types of piles are used when installing a pile-grillage foundation. When choosing piles, the characteristics of the soil and load are taken into account. For private houses, bored and screw piles are most often chosen.

Classification by degree of depth

Depending on the position relative to the ground, there are 3 types of grillage:

• Low or recessed. Its peculiarity lies in the fact that it is installed below ground level, that is, in the ground. The grillage is placed on a sand cushion.
• Ground. Located at surface level.
• Tall or hanging. It is located above ground level on high supports. If groundwater flows close to the surface, this type of grillage is used.

Source nauka-i-religia.ru

Recessed grillages are used only in case of emergency, since their installation is comparable in complexity to the installation of a shallow strip foundation: it is necessary to dig a foundation pit, equip a draining sand cushion, make a formwork, but also install piles.

Unlike buried and ground grillages, hanging grillages are not as labor-intensive and, as a result, less expensive.

Stages of installation of a pile foundation with a grillage

The equipment of the pile-grillage foundation is divided into the preparatory stage and the installation itself. At each stage, you have to perform several types of work:

Preliminary work

• For the construction of the foundation, first of all, it is necessary project, which is created on the basis of load calculations, the estimated depth of piles, what materials the foundation is planned from.

A project from a professional is a guarantee of safety, long service life, as well as savings in materials and finances Source nl.decorexpro.com

• Then site is being prepared: debris, topsoil and plant roots are removed.
• Held territory marking: mark the location of supports, grillage, load-bearing structures of partitions.

Attention! Deviation from the project is always the cause of negative consequences, such as the curvature of the foundation, the occurrence of unforeseen items of expenditure, and more. Therefore, it is important that the project is drawn up by professionals and is tied to the area.

The work of a "professional" is immediately visible Source blog-potolok.ru

• A trench is dug under the grillage. Its walls and bottom are checked for evenness with a level. After that, a sand cushion is laid and compacted.
• Drilling wells for supports, on the bottom of which a pillow of sand is also laid. Waterproofing is laid in the pit: you can use a special film, several layers of roofing material, plastic pipes.

Installation technology of pile-grillage foundation

• For the grillage, reinforced concrete beams are used or a monolithic tape is poured. A wooden rectangular formwork is prepared for it, which is fixed with supports and lintels. At this stage, it is also worth taking care of sewers and pipelines.

Photo of a pile grillage foundation - after the concrete dries, the formwork is removed Source bestroof.ru

• To increase the strength of the structure, a reinforced frame is placed in the well - 4 metal rods each, tied with wire. Then the concrete is poured. The tape is also reinforced.
• Next, concrete is poured first into the wells, then into the formwork. The setting of concrete will take at least 10 days, after which the formwork is dismantled.

How is the need for foundation materials calculated?

An accurate calculation can only be performed by a specialist - a civil engineer, who will rely on the requirements of SNiP and a number of indicators such as the strength of the supports, grillage, the bearing capacity of the foundation, the soil resistance force, the degree of shrinkage of the support under the influence of a vertical load, etc. The specialist will determine the depth of immersion of the supports, their diameter, number, type of grillage and develop a diagram.

For a person without a specialized education, the calculations of a pile grillage foundation look something like this Source ask.fm

When calculating the number of supports, they proceed primarily from the load on the foundation, which consists of several indicators. Here it is necessary to know the mass of load-bearing walls, partitions, roofs, floor slabs, i.e., the entire mass of the building above the foundation. The payload produced by residents, household items and all other things is also taken into account. In calculations for private houses, an indicator equal to 150 kg / m² is used.

The last parameter for determining the total load is the weight of the snow mass that can accumulate on the roof in winter. The value of 180 kg / m² is mainly used, but for a number of regions of the country it is somewhat different. The resulting amount of loads is multiplied by a safety factor, which is 1.1 (sometimes 1.2 is used). Next, you can calculate the load on one pile.

It would be useful to add that the online calculators for calculating materials that are common on the network should be treated very carefully. They may not take into account a number of important parameters.

Video description

An example of an online calculator, see the video:

Installing additional items

When erecting a pile-grillage foundation, it is necessary to equip ventilation holes in the foundation and lay pipes that can be used for heating, sewer, plumbing systems and other communications. If you do not take care of the engineering and technical equipment of the house in time, later you will have to partially destroy the grillage to install them.

For the preservation of the foundation, it is imperative to provide vents for ventilation Source repairstroy.net

Requirements for creating a high-quality grillage foundation

Since the main loads on the grillage are bending forces, one of the key points in creating a grillage foundation is reinforcement, which significantly increases the strength of the structure.

Source: stroidominvest.ru

The second significant point concerns the hardening time of the concrete structure - and this is a whole month. The grillage will be able to withstand the proper loads only after the concrete has completely hardened.

Possible errors in the arrangement of the foundation

• The piles are not firmly fastened to the grillage - thermal expansion with seasonal temperature fluctuations will soon loosen the attachment point.
• The piles are laid too shallow. Here, both excessive shrinkage of the foundation and extrusion of piles that are not fixed in the layer below the freezing of the ground by the forces of soil heaving are not ruled out. All this can lead to the destruction of the building.
• Inaccurate calculations. It's just a powder keg - you never know what might happen.

Video description

About the features of the pile strip foundation, see the video:

These are typical, but far from all, oversights that unskilled builders make. There are many stories on the Internet about what went wrong during self-construction, but even knowing other people's mistakes often does not compensate for the presence of real skills and experience. As a result, everyone should mind their own business.

Calculate and build must be qualified specialists Source pinterest.com

What determines the cost of srf

If the project provides for the installation of a pile grillage foundation, then what determines the cost of the cff is determined by a whole group of factors:

• the scale of the building;
• type and number of supports, their diameter and length;
• dimensions of the foundation tape;
• use of special equipment;
• region;
• construction company policy.

Online foundation calculator

To find out the approximate cost of a "grillage on piles" foundation, use the following calculator:

Video description

Visually about the cost of a pile-grillage foundation, see the video:

Conclusion

A pile-grillage foundation is considered more reliable than a pile foundation, and more profitable than a strip one, and in some situations it is the only possible one. But competently make calculations and equip it only by qualified specialists. Otherwise, such a foundation will have insufficient strength or excess cost, which equally levels out all its advantages.