The Best-Stroy company drills piles with a diameter of 150 to 1500 mm to any depth up to 45 meters - as part of the technology of bored, drilled injection, drilled secant, driven, bored and even driven piles, leader drilling for piles.

Drilling for driven piles carried out in dense soils, when immersion by driving does not allow reaching the design immersion depth to the load-bearing layer. Due to the fact that the pile column enters the finished well more easily, the impact force can be less. As a result, you can use cheaper pile elements without reinforcement. The method is used to ensure verticality in heterogeneous soils, as well as for passing heaving soils. Piling work can be carried out all year round in any type of soil except rocky soil. Special equipment used: pile installation with drilling auger equipment.

Drilling under is performed by tracked drilling rigs for rotary and rotary-impact drilling SOILMEC, BAUER, ENTECO and other brands. Using auger equipment, Kelly rods. With excavation in inventory casing pipes or under the protection of bentonite clay solution. And also using the technology of rolling out soil without excavating it. At the same time, the diameter of the wells according to the technology can reach from 150 to 1500 mm.

Drilling under the protection of inventory casing pipes

provides a high-quality well in any type of soil, does not allow the walls of the well to crumble, which could lead to the formation of cavities in the monolith that are not filled with concrete. And therefore, it would lead to its fracture or deformation under load. After the reinforcement cage is immersed and the well is filled with concrete, the casing pipe is removed.

Drilling under mud protection performs the same function - protecting the walls from crumbling. During the process of filling a well with concrete, a light bentonite solution is forced to the surface.

Installation of drilled injection piles requires drilling using a continuous hollow auger technology, through which concrete solution is then supplied under pressure simultaneously with the auger being removed.

Drilling under is carried out in a special order according to the technological map for the wells. First after one. Filling in progress. The distance between the axes is less than the diameter - this is done so that adjacent elements interlock with each other, forming a wall. Then the soil is drilled between the finished columns with their partial cross-section. The concrete solution is poured and after setting the wall is ready.

Leader drilling for piles carried out in the following cases:

• when installed by driving or vibrating into frozen soil,
• into dense soil,
• to reduce the dynamic impact on the foundations of adjacent buildings in dense buildings,
• for making pits.

In accordance with SNiP, wells must have a cross-section up to 50 mm smaller than the cross-section of piles.

Drilling wells for piles allows you to:

• reduce production time
• reduce costs when driving, vibrating or pressing
• ensure immersion to the designed depth regardless of soil characteristics
• ensure verticality, despite any difficult ground conditions
• to comply with the full technological cycle for the production of drilled BNS of proper quality.

Rent a drilling rig in Moscow for wells

A large fleet of special equipment is at your service - we are for drilling wells BAUER BG22, BAUER BG25, BAUER BG28, BAUER BG36, BAUER BG28, Enteco E-400, Soilmec R625, Mait HR130, Casagrande C40. Most of them are capable of drilling under piles with an auger, a kelly bar, under the protection of inventory casing pipes, as well as using the continuous hollow auger method (CFA / NPSH) and a soil roller (with its compaction in the face without excavation, which reduces removal costs soil).

Pile foundations under houses and other buildings in many cases turn out to be the best solution. But in order for such a structure to last long enough and not fail, it is necessary to carefully drill the recesses. This work has many subtleties and nuances, which will be discussed in detail in this article.

Peculiarities

Drilling for piles allows:

• build something in a shorter time;
• reduce the cost of work;
• guarantee real stability and strength of the building.

Drilling wells under piles is really necessary when it is necessary to build a house in places with an increased risk of earthquakes or on an area with low-density soil. Such drilling can be done in any season, the type of climate does not matter. Such advantages have allowed construction drilling to become one of the leading methods for preparing excavations.

Drillers are hired in cases where it is necessary to strengthen the foundation without affecting the characteristics of previously erected buildings. Drilling can also keep slopes stationary.

Tools

Pile drilling techniques can be very diverse. In most cases, vehicles with wheeled, auger or tracked propulsion are used for this purpose.

To make a well for a pile, use:

• universal drilling rigs for wells;
• pile driving drilling units;
• drilling and crane complexes.

The differences between them in general and between individual models in particular are determined, first of all, by the level of productivity, the specifics of the control bodies and the size of the wells created. In terms of cost of work and accessibility for non-professionals, it is difficult to find analogues of a hand drill.

Low productivity is justified by the fact that expensive equipment and trained specialists are not needed. But in situations where speed is important or the soil is very difficult, it is worth using a hole drill. Such devices are mounted on wheeled and tracked platforms. If the conditions are difficult, even highly specialized equipment has to be brought in.

A driller helps make it easier to do the work alone. The reinforced design of the popular TISE version allows for an enlarged heel at the lowest point. As a result, the base goes below the freezing zone, and with the same load-bearing characteristics, the solution consumption is reduced by 3-4 times compared to alternative technologies. In addition, for a foundation with identical properties, it will be necessary to install fewer piles than usual, and their diameter will be reduced.

Process steps

To drill a hole with your own hands or with the help of specialists to the required depth, you must strictly follow the technology.

A typical work algorithm is as follows:

• installation of drilling equipment and its fixation;
• penetration to the designed depth and diameter;
• conservation work using a clay solution or inserting a casing pipe;
• saturating the resulting cavity with concrete solution.

Experts pay special attention to the fact that both the prepared pit and the concrete poured into it have a short shelf life. According to the generally accepted standard, a maximum of 8 hours should pass from lifting the drill to pouring the last drop of concrete.

There are also requirements for preparatory work, which look like this:

• Fertile soil is removed (up to 150 mm over the entire area).
• A pile field is planned at a selected elevation.
• A fence from outsiders is being installed.
• The site is formatted, and then the evenness of the surface is checked again.

• Pillows for the work itself and the passage of cars are filled up.
• Route lines are being prepared for drilling systems using reinforced concrete slabs.
• Drainage channels are being organized.
• Lighting devices are connected (only if you need to drill around the clock or during reduced daylight hours).
• The arrangement of drilling systems and the required materials and products is carried out.

Methods

Rotary drilling of wells consists of initially passing through a leader part equal in length to the casing section. This method has proven itself very well in a variety of geological conditions, with unequal soil saturation with water.

The use of a standard auger drill (an oblong rod with a high-strength tip and helical blades) allows you to lift crushed soil upward as quickly as possible. The rate of passage of holes can reach 120 cm per minute. The drilling complex periodically pulls out and lifts the working part, freeing it from adhering soil.

High-quality adherence to technological principles will make it possible to form holes up to 10 m in length during the working cycle, from one lifting of the drill to another. Another option for penetration involves covering the walls of the hole with an inventory pipe formed by single steel sections. Each fragment can reach 6 m in length. At the bottom there is a cutting part with teeth made of hard alloys. When the drill moves down, the pile is simultaneously pressed in, it blocks the seepage of water from the soil and prevents the walls from collapsing.

Having reached the zero level, determined by the foundation design and SNiP for a specific area, the auger drill is raised upward. Water that has leaked from the soil into the prepared cavity is removed. But a reinforcing frame is immersed there. The last step is to saturate the empty space with concrete.

Another type of drilling is the use of a rod auger, which supplies the solution through the cavity in the rod itself. This approach ensures the formation of 400 linear meters. m. channels for a standard 8 hours. In this case, the channels can be large in diameter (from 50 cm) and reach 30 m in depth each. This is achieved by systematically increasing the length of the auger until it reaches a given level. The saturation of the cavity with the solution is combined in time with the raising of the mast, this helps to create an array for cast-in-place piles. Remember that concrete is injected under pressure and therefore becomes stronger than usual.

If the introduction of a reinforcing frame is provided, it is simply pressed mechanically into small wells, and introduced into large ones using a vibrating loading machine. A typical auger works well in dry or nearly dry soil. There is no need to prepare and strengthen the internal cavities of wells.

The approach with an inventory pipe also has its advantages. Only it can form channels with a diameter of 1500 mm in very wet soil and quicksand. Wet drilling helps strengthen the body of a well going through medium-density clay or sand.

It is the wet method that is considered the least noisy, and it also does not destroy the soil layers as a whole. In some places the channel can widen up to 350 cm, which guarantees the highest stability of the base.

Leader drilling is designed to solve such a problem as vertical installation of supports in dense earth. It is precisely used in the winter months, when the soil density is greatest. It is also important that the volume and vibration level are relatively low.

The disadvantage of “leaders” is the mandatory preparation for drilling. It is also worth considering that the well will be 30-50 mm smaller than a reinforced concrete structure, the reduction in depth will be approximately 1 m.

• A layer of sand of increased density was discovered.
• The top layer of soil is hard.
• The site is located on permafrost.
• The construction site is abundantly filled with rocky soil.
• The piles will have to be driven to great depths.
• The territory is filled with dispersed soil with a very low density.

Test drilling for laying piles allows you to once again weigh all the subtleties and nuances. In some cases, an error can be very expensive, and it is discovered after all construction work has been completed. The properties of the soil vary over a wide range in space, and if at 10 - 15 m it is completely solid, this does not mean that there will not be unexpected phenomena in a particular place. They include voids, aquifers, loose particles and the retreat of a really strong layer to an unusually great depth. Quite often there is a problem such as fluctuations in frost lines.

A hand drill is unacceptable if the depth of penetration of the pile must exceed 7 m. By simplifying the work using gasoline or special equipment, one should strive to reduce the overall work period to a minimum. Even a slight rain or the beginning of snow melting can collapse a well that has just been prepared at the cost of great effort.

It will not be possible to remove the soil and revive the site; you can only drill the hole again. The fastest option (although not always acceptable) is screw piles, which simultaneously serve as a drill and a support.

The stability of buildings is ensured by a reliable foundation. Among the various types of foundations, the pile type is widely used, ensuring the durability of buildings on problem soils and in seismically active zones. To construct the pile base, bored piles with a length of more than 15 meters are used. Rapid drilling of piles occurs through the use of special equipment. The soil is removed, then the reinforcement is installed and concrete solution is injected into the cavity. Let us consider in detail how piles are installed using this technology.

Drilling piles - purpose and sequence of actions when performing drilling operations

Drilling wells for piles is a practice-tested technique designed to solve the following problems:

• construction of new foundations with increased resistance to movement of problematic soil;
• previously constructed buildings and increasing the stability of building structures.

A significant feature of the technology is the ability to carry out drilling activities throughout the year. The drilling process does not have a negative impact on the foundations of nearby buildings. The formation of channels in the ground and the installation of pile supports are stages of the overall process of creating a pile foundation. It is important to maintain continuity of operation and adhere to technology requirements.

The drilling process does not have a negative impact on the foundations of nearby buildings

Work on drilling channels and installing piles is carried out according to the following algorithm:

• installation of special equipment for drilling operations is carried out;
• measures are taken to ensure that the equipment remains stationary;
• a well of a given depth and diameter is drilled depending on the requirements of the project;
• the surface of the pit is preserved with clay or the inventory pipe is lowered;
• installed and fixed in the drilled channel;
• The cavity with the reinforcement grid is filled with the prepared concrete mixture.

When performing drilling activities, consider the following points:

• use wire for reinforcing structures with a diameter of 8-14 mm;
• use branded concrete made from M400 or M500 cement;
• do not allow rock to fall into the drilled hole;
• Carry out concreting within 8 hours after drilling.

Please note that the useful life of the concrete mixture and the drilled well is limited. After a short time, the concrete and the cavity in the ground become unsuitable for further work. During the shift, the formed cavities for bored piles should be concreted.

Drilling wells for piles - the use of special machinery and equipment

To make holes in the ground under the bored supports of a pile foundation, various techniques are used:

The use of drilling machines allows you to perform an increased amount of work in a limited time

• special equipment is used that moves independently on the construction site using pneumatic wheels or tracks. The use of industrial drilling rigs allows an increased amount of work to be completed in a limited time. Specialized equipment allows you to drill wells more than 40 meters deep with a diameter of up to one and a half meters;
• hand-held devices are used to create cylindrical cavities in the soil. The design features of the hand tool make it possible to form conical cavities in the lower part of the well, increasing the area of ​​the supporting surface. The diameter of the working body of hand drills is no more than 30 cm. Hand devices are actively used in the field of private house construction.

The use of drilling machines with increased productivity allows you to reduce the duration of drilling operations and significantly save money. Drilling rigs are mounted on powerful vehicles, which allows you to quickly move to complete assigned tasks.

To accelerate the formation of pits, the following types of drilling machines are used:

• drilling rig for drilling wells for piles;
• drilling and crane installation with hydraulic drive and blade drill;
• hydraulically controlled pile driving and drilling machine.

According to the principle of operation, mobile drilling rigs are divided into the following types:

• units equipped with a solid auger, which grows as it is immersed in the pit;
• installations with a drilling working body and a tubular shell for supplying concrete solution into the cavity.

When choosing equipment to solve specific problems, take into account the complexity of the task, the volume of drilling work, as well as the diameter and length of the wells for pile supports.

The base is characterized by high technical characteristics if the work production technology is correctly followed.

Drilling for bored piles - drilling technology

The process of drilling pits for installing pile supports is a set of activities, including the following stages:

• preparatory work related to geodetic surveys and transfer of coordinates for the location of supports to the construction site;
• delivery to the work site of the necessary materials, as well as drilling equipment, which is placed in accordance with the requirements of the project documentation;
• direct implementation of drilling activities with access to the depth specified by the project and installation of the reinforcing frame;
• installation, if necessary, of a casing pipe and filling the formed cavity with concrete mortar.

After the concrete solution has reached operational hardness, the pile support is ready for further use. This technology is used to build a pile foundation intended for low-rise frame-type buildings and buildings made of timber and rounded logs. Let us dwell in more detail on the specifics of the preparatory work and consider in detail the drilling methods used.

Construction of bored piles: preparatory activities

Drilling pits is preceded by a certain preparation, during which the following work is performed:

The set of measures is the process of drilling pits for installing pile supports

• design documentation is being developed for the facility under construction. The technological map attached to the project contains information on the formation of each channel and the entire pile field;
• the necessary tools, equipment and materials are prepared to carry out drilling activities. The choice of equipment used depends on the drilling method, the size of the pile and the condition of the soil.

At the design stage, the design load is also taken into account, the magnitude of which depends on the characteristics of the structure.

Preparatory activities include the following work:

• removal of the top layer of soil, the thickness of which is 15-20 cm, over the entire area of ​​the construction site;
• layout of the pile field of the future foundation, taking into account all the necessary design requirements;
• installation of fences around the perimeter of the work site to restrict access of unauthorized persons to the work site;
• laying out the foundation site according to the documentation, followed by checking the elevations;
• formation of a crushed stone cushion over the area of ​​the site for unhindered movement of drilling equipment;
• laying reinforced concrete panels to facilitate the movement of heavy drilling rigs around the construction site;
• equipment for pumping water necessary for flushing wells and extracting soil;
• connection of lighting installations that facilitate work in the dark;
• placement of drilling equipment at the construction site and ensuring its fixed position.

After completion of preparation, the materials necessary to carry out drilling activities are delivered to the work site.

At the design stage, drilling technology is selected to solve a specific design problem

How are bored piles constructed - specifics of the technology

Drilling wells for piles is carried out using various methods:

• using a standard blade auger equipped with a reinforced tip;
• using an expandable inventory pipe consisting of separate sections;
• a combined method involving auger drilling with subsequent supply of concrete into the cavity.

Each method of well formation has its own characteristics. Let's look at them in more detail.

Drilling piles using auger-type technological equipment

The above method of performing drilling work involves the use of special drilling equipment equipped with a standard auger. The working body is a longitudinal rod with blades arranged along a helical line and a shank with a reinforced tip.

The optimally selected pitch of the helical blades, as well as the angle of inclination of the turns, ensures accelerated extraction of mined-out soil to the zero level.

The main features of the operation of equipment equipped with a standard blade auger:

• the speed of penetration of the well by the working body increased to 120 cm/min;
• cyclic immersion and lifting of the auger device with extraction of settled soil;
• the ability to pass through a well with a depth of 8-10 m in one step without lifting the blade auger.

The design features of the working body and the functionality of the equipment make it possible to form a cavity in the lower part of the channel using an auger drill. The increased area of ​​the supporting platform and the conical shape of the cavity are provided with the help of an expansion device, immersed simultaneously with the screw. At a given depth, the hinge mechanism changes the angular position of the nozzle, which forms an extension of a given shape and size in the lower part of the hole. This allows you to increase the load capacity of the bored pile.

A certain type of piles and their driving technology are selected depending on data from engineering, geodetic and geological surveys

Drilling wells for piles using core technology with concreting

This drilling method allows you to create and concrete a cavity in the ground. Equipment with a rod working body is used, the design of which allows the concrete mixture to be supplied through a channel in the auger pipe.

The technological equipment and working tools used allow:

• form multiple wells per shift, the total length of which reaches 350-400 m;
• immerse the working body in the soil when performing drilling operations to a depth of 30-40 m;
• ensure the diameter of the channel formed by immersing the rod tool in the range of 50-100 cm and above;
• gradually increase the length of the bladed auger sections until the specified hole depth is achieved;
• pump the prepared concrete mixture into the well using a special pumping unit;
• raise the working mast simultaneously with the supply of concrete mixture into the drilled cavity.

During the process of injection of concrete solution, the walls of the well are compacted, which has a positive effect on the strength characteristics of the channel. The reinforcement cage is immersed into the well by pressing or using a vibratory driver. This drilling method can significantly reduce the construction cycle for the construction of a pile foundation by combining drilling and concreting operations.

Drilling for bored piles with protection of part of the well using pipes

The technology for performing drilling activities provides for the possibility of using inventory pipes to protect the surface of a channel formed in the ground.

An inventory pipe is a special drilling equipment that consists of the following components:

• separate tubular sections that are easily connected using locks. The length of each element does not exceed 6 m;
• cutting head with a toothed surface. The nozzle is made of carbide material and is attached to the bottom of the pipe.

The drilling process is carried out according to the following algorithm:

1. High-speed excavation of the soil massif with a drill is carried out. When the working body rotates and plunges into the well, the soil is gradually removed from the formed channel.
2. Simultaneously with drilling, an inventory pipe is pressed into the soil. The metal shell of the protective pipe makes it difficult for groundwater to penetrate into the well and prevents the walls of the pit from collapsing.

After completing the operations to form the recess, the following operations are performed:

1. The auger drill is pulled out to the zero mark.
2. Water that has penetrated through the soil into the pit is pumped out.
3. The reinforcing grid is gradually lowered into the well.

The process of forming a bored pile is completed by pumping a pre-prepared concrete mixture into a cavity formed in the ground. Special equipment is used for continuous supply of concrete solution.

The technology allows drilling to be carried out on problematic soils characterized by high moisture concentrations, as well as on dry soils.

Let's sum it up

Using various technological techniques, professional builders drill for bored piles. Pile supports ensure the strength of the foundation and increase the stability of building structures. To ensure the quality of drilling work, the technology requirements must be observed and the requirements of the design documentation must be followed. The use of industrial drilling rigs makes it possible to reduce the duration of construction activities and perform an increased volume of work.

In a vertical position in areas with dense soil. This method is most relevant in winter, because it facilitates the process of driving in the tongue when laying the foundation.

The popularity of this technology is increasing every year. Leader drilling allows not only to reduce soil resistance, but also to immerse the structure to great depth. In addition, noise and vibration levels are reduced during work. This is one of the advantages of the method.

Peculiarities

At the design stage, specialists determine the method of laying the foundation, and also clarify the requirements for the technology and performers.

Drilling of leader wells is carried out only after preparatory work has been carried out. First of all, the dimensions of the piles are determined. The diameter of the leader wells should be 3-5 centimeters smaller than the diameter of the reinforced concrete structure.

All work must be carried out in accordance with SNiP. Leading is carried out before driving reinforced concrete structures into the ground. This technology is used very often due to the reduction in vibration and noise levels. After all, piles are driven into the ground quickly and without much difficulty.

The diameter of the auger used when drilling wells depends on what kind of soil is at the base. The depth should be approximately 1 meter less than the depth of the pile. It is worth noting that the driving of reinforced concrete structures, as well as preliminary drilling, are carefully planned by many specialists. This allows you to fully comply with the technology and optimally place the piles in each specific case.

In what situations is such drilling required?

Lead drilling of wells for piles is often used when laying foundations based on piles. Moreover, the design can be of any volume and varying complexity. Most often, this method is used in the following cases:

• If during a geological survey a layer of compacted sand was identified. With impact paving, such soil is almost impossible to pass through. As a result, leader drilling for piles is carried out.
• If the top soil layer is dense. With the impact method of laying piles, the reinforced concrete structure may be destroyed or deformed. Preliminary drilling allows you to penetrate the problematic soil layer without complications.
• If work is carried out on permanently frozen ground. This soil is quite dense. To avoid problems, leader drilling is recommended.
• If the site is dominated by rocky soil. For the driving technique, rocks are an insurmountable barrier.
• If the piles are placed at a significant depth. In this case, pile failure may occur. As a result, it is not possible to reach the required level without drilling wells.
• If the area where the foundation is laid is dominated by dispersed soil with a minimum density. In this case, the guiding function of drilling is especially appreciated.

Application

This method of laying piles is often used when laying out foundations in areas close to buildings. This method allows you to reduce the noise level during work, as well as reduce vibrations when hammering reinforced concrete structures. Leader drilling can be carried out in densely populated areas located within the city.

This technology can significantly speed up the process of laying a pile foundation. Such drilling does not violate the integrity of reinforced concrete structures. At the same time, the technology makes it possible to achieve the desired depth, while ensuring rapid passage of dangerous and problematic areas at the construction site.

How does drilling for piles take place?

Leading is carried out using drilling rotators equipped with them. They replace pile hammers. The key point is to maintain verticality. Only in this case can the work be done efficiently. This is ensured by drilling rotators.

When carrying out work, soil removal is required. The manipulation is performed manually. If this is not done, the excess soil will not allow the piles to be installed. Due to the removed soil, the mark increases by about 50 centimeters.

Stages of work

The process of leader drilling and piling can be divided into several stages:

• The places where the piles will be driven are marked with dots on the site.
• Special equipment is installed. The units are installed in the marked locations.
• The equipment is prepared, verticality indicators are checked.
• Wells are drilled using special pits.
• Reinforced concrete structures are driven into the ground.
• An examination of each installed pile is carried out. They are handed over to a technical supervision representative.

When performing leader drilling, several types of augers can be used: continuous and composite design. In the first case, creating a well is a non-stop process. This saves time and also ensures high quality of work performed.

Benefits of technology

The popularity of leader drilling can be explained by its advantages. Among the advantages of this technology are:

• The ability to install piles on a site with different types of soil, as well as with any technical characteristics.
• The technology makes it possible to significantly increase the depth of laying reinforced concrete structures.
• Compliance with all rules for installing piles. The verticality indicator is taken into account.
• High quality of work performed.
• Reduced vibration levels for neighboring buildings when driving piles.

Disadvantages of technology

The disadvantages of leader drilling include:

• Tangible material costs that arise when overcoming some bureaucratic obstacles.
• Involvement of specialists, as well as the use of equipment.

Despite the large number of advantages, the technology also has one more minor drawback. This is the price of the work performed. The cost of leader drilling depends on several indicators. First of all, this is the depth of the laying, as well as the type of soil on the site. On average, this figure is 300-1500 rubles per 1 meter.

In conclusion

Leader drilling technology is constantly being improved. After all, this method is used in places where it is impossible to do without additional soil treatment. This technology is relevant when driving reinforced concrete structures in problem areas. Special equipment greatly simplifies the process of laying the foundation for a future foundation. The main thing is to follow all the recommendations of specialists and follow the rules when performing work.