A good solution for the construction of large “budget” baths; in terms of financial costs it is considered one of the cheapest options, and in terms of load-bearing characteristics it can be classified as universally used. It is recommended to build such foundations on almost all types of soil; only very rocky soils can create problems. In order for the bored foundation not to disappoint developers, it is necessary to strictly follow all recommendations and carry out technological operations taking into account existing building codes and rules.
From the name you can guess that for such a foundation you need to drill a hole in the ground and fill it with concrete. The drilling depth depends on the physical characteristics of the soil and the climatic zone of residence.
Important: the lower part of the concrete column must be located below the maximum freezing level of the ground in winter.
For bored foundations Sand cushions cannot be used to compensate for swelling (this method is used in shallow strip foundations), this is due to several reasons. The main one is that the abutment area is insignificant; the presence of sand will cause a significant decrease in the bearing capacity of the piles. And if you also keep in mind that the area of the piles is already small, then you will have to either increase their number (which is expensive and time-consuming) or their diameter, and this will also cause an increase in cost.
Professional builders recommend drilling wells to the clay layer; in different areas it is located at different depths. First you need to try to find out the depth of its occurrence by drilling the first well. Of course, it is not recommended to make it very deep, but it will be a shame if you “fall short” of 10–15 centimeters to the clay layer.
Some builders advise to increase the area of the lower part of the pile during pouring by raising the formwork or pipe; the concrete will flow out a little and form an expansion.
Theoretically, everything is correct, but I would just like to see in practice how these smart advisers will hold the pipe for several days and wait for the concrete below to cool. And do this with all the piles!
But that's not all. The diameter of the hole made should correspond to the maximum extent with the diameter of the formwork, the difference is only a few centimeters. I wonder if these few centimeters play a decisive role in the bearing capacity of the pile? Decide for yourself whether to take this advice or not.
Table. Pile bearing capacity
| Diameter of the bored pile base, mm | 100 | 150 | 200 | 250 | 300 | 400 | |
|---|---|---|---|---|---|---|---|
| Values of average design soil resistance, kg/cm2 | Approximate values of bearing capacity of piles, kg | ||||||
| Dense 4.5 | 350 | 790 | 1400 | 2200 | 3100 | 5600 | |
| Sands are gravelly and coarse, regardless of their humidity | Average 3.5 | 270 | 610 | 1100 | 1700 | 2450 | 4400 |
| Dense 3.5 | 270 | 610 | 1100 | 1700 | 2450 | 4400 | |
| Sands of medium coarseness, regardless of their humidity | Average 2.5 | 200 | 440 | 780 | 1220 | 1750 | 3100 |
| Sands are fine, low-moisture | Dense 3 | 230 | 530 | 940 | 1450 | 2100 | 3750 |
| Sands are fine, low-moisture | Middle 2 | 160 | 350 | 630 | 980 | 1400 | 2500 |
| Dense 3.5 | 270 | 610 | 1100 | 1700 | 2450 | 4400 | |
| The sands are fine, very wet and saturated with water. | Average 2.5 | 200 | 440 | 780 | 1220 | 1750 | 3100 |
| Hard clays | Tight 6 | 470 | 1050 | 1850 | 2940 | 4230 | 7530 |
| Hard clays | Middle 3 | 230 | 530 | 940 | 1450 | 2100 | 3750 |
| Lamellar clays | Dense 3 | 230 | 530 | 940 | 1450 | 2100 | 3750 |
| Lamellar clays | Average 1 | 80 | 170 | 310 | 490 | 700 | 1250 |
| Tight 6 | 470 | 1050 | 1850 | 2940 | 4230 | 7530 | |
| Coarse soils, crushed stone, pebbles, gravel | Average 5 | 390 | 1550 | 2450 | 3500 | 6250 | 3760 |
How to drill a hole for piles
There are three methods of drilling wells, each of them has the right to use.
What is needed? Elementary drill, physical strength, patience and perseverance.
Advantages - it seems cheap, there is no need to pay for equipment rental. But it’s cheap only if you don’t value your work and time at all, which can be used more profitably.
Another disadvantage is that it is very difficult to manually drill wells in hard soils. And in terms of depth, you will not be able to achieve the desired indicators.
Prices for hand drill
hand drill
Video - Drilling holes by hand
Drilling wells with a gasoline drill
Drilling wells manually with a gasoline drill 
Manual drilling of wells is a rather tedious and time-consuming process.
The best option is to do the work much easier and faster. It is possible to accurately plan the number of holes per day, and this is very important for the quality performance of the following work. We will talk about this method in detail later.
Video - Drilling holes with a hand-held gasoline drill
Today there are a large number various kinds equipment for drilling wells. Using special equipment allows you to drill wells for the entire foundation of the bathhouse in one day.
One technique must approach each well, the second has a long boom, which gives it the opportunity to drill several wells from one place. Each has its own advantages and disadvantages. But everyone has general requirement – further work for driving piles with concrete should be carried out as soon as possible. If the work is interrupted by long rains, then big problems will arise, the walls of the holes will collapse, and the holes will have to be cleaned. But you can’t do this kind of work with a shovel; you’ll have to call the equipment again. All this has a very negative impact on the final cost of a bored foundation.
Video - Drilling holes with a Bobcat.
The construction of a bored foundation has many specific features, depending both on the characteristics of the sites, and on the qualifications of the performers and the financial capabilities of the developers. It is impossible to consider all options; you need to know specific conditions. We will try to give maximum universal advice that is suitable for most methods of constructing bored foundations for wooden baths.
Step-by-step instructions for building a foundation
Initial data: drilling holes for piles is carried out with a portable gasoline drill, concrete pipes are used as formwork, a hanging grillage is made of channel bars, the diameter of the piles is 20 centimeters. This option is suitable for most baths.
In terms of the degree of “mechanization” it occupies an average place, and in terms of the quality of the foundation it is in no way inferior to drilling options using special equipment.
We chose concrete pipes as formwork, we need to explain our choice, because there are several other options.
Board formwork. It is difficult to do; the geometry of the wells is far from the required one. A few more disadvantages: wooden formwork takes up a lot of useful space in the hole and is difficult to disassemble.
Not a bad solution, but can’t be found on the open market plastic pipes large diameter is problematic. In addition, they can only shape the geometry of concrete, and do not support any loads themselves. The concrete pipes we have chosen serve as excellent reinforcement for a bored pile.
Ruberoid. There are such options, but we categorically do not recommend using them for several reasons.
In the event of a large collapse of the pit walls, they will not hold the ground, and the hole will have to be drilled again. But this is not the main thing. The pile works with the calculated indicators only when it is in a strictly vertical position. Any, even slight, slope exponentially reduces its load-bearing capacity. During concrete pouring, the uncured mass may deviate from the vertical.
If your formwork is rigid, then returning it to the desired position will not be difficult. But if you use roofing felt as formwork, then big problems arise. In the best case, you will have to fill the entire volume of the hole with concrete, and this is an overconsumption of materials. Then why waste time and money on roofing felt?
The option we have chosen for constructing a bored foundation is not an axiom; everyone can make a decision taking into account their own conditions. The only request is that before choosing the final type of bored foundations, you need to understand the consequences of certain changes in design and technology.
Prices for external plastic pipes
external plastic pipes
Stages of construction of a bored foundation
Before starting work, you need to prepare all the materials and tools, determine the number of people working and the time allowance. Due to the fact that we will be drilling holes for the piles with a portable gasoline drill, at least two people must work. Concrete is needed in small quantities and can be made with a concrete mixer or by hand. The second option is preferable - you can more accurately calculate the amount of concrete for each pile and prepare only the required volume.
Marking the pile field on the ground
We hope that there is a drawing or, at least, a sketch for the foundation; you know the number of piles and the distance between them.
markup pile field- scheme
Step 1. Measure the width of the bathhouse on the ground, drive in two pegs, and stretch a rope between them. Tie the second rope with one end to the driven peg, and the other to the second free one. The length of the rope should be 0.5÷1.0 m greater than the length of the bathhouse.
Now you need to find the right angle between the two ropes. It is done like this:
Such operations need to be done in all corners of the bathhouse foundation. It is advisable to check the correctness of the markings by measuring the diagonals; the spread in length should not exceed two centimeters. If it is more, you will have to move the pegs a little to align the diagonal values. Two centimeters are tenths of a degree of angle; such an error can be easily eliminated during the assembly of the log house. Experienced builders get everything right the first time; for absolutely all types of construction work, greater precision is not required. They use not only legs with dimensions of one meter; they are not too lazy to remember other numbers.
For boats of 1.5 meters, the hypotenuse is equal to 2.23 centimeters; for boats of 2 meters, the hypotenuse is equal to 2.82 meters. The larger the sides of a right triangle, the higher the accuracy of the angle, then you do not need to measure the diagonals to check. Remember these numbers too, they are needed to carry out a large number of construction works; rarely do any structures do without a right angle.
Knowing these simple rules will allow you to mark the foundation in 10–15 minutes; you do not need to prepare various smart devices and rearrange them from place to place. Each construction operation can be performed much faster and better, but for this you need to have experience.
Step 2 Pegs must be driven in at the locations of the piles. In all corners it is mandatory that the distance between them is no more than two meters. Due to the fact that no one makes accurate calculations of the strength of the foundation, it is better to be safe with the number of piles.
Step 1. Drill holes for the piles with a gasoline drill. If you have a casing diameter of 20 centimeters, then the diameter of the drill should be approximately 30 centimeters. The point is that you should give a margin in size. It is unlikely that it will be possible to drill a hole at an exact 90° angle, and the pile must be vertical, which means that there must be free space for it correct installation. Well, the sides may crumble slightly; in this case, you also need a spare size.
There are drills on sale that you can use to work on your own, but they are technical specifications in terms of power, diameter and depth of the holes, they are not suitable for the construction of bored foundations. Although, if you read the advertising brochures, you can believe in the effectiveness of this technique. This is not true; the maximum diameter of holes that low-power motor drills can drill is twenty centimeters. Firstly, this is not enough for our case. Secondly, you should never work with equipment at the maximum values of its technical capabilities. Thirdly, this drill has insufficient gasoline engine power. On hard soils it overheats, and work has to be stopped frequently to cool the cylinder head and gearbox.
It is better to use a more powerful motor drill. Some modifications can make holes with a diameter of up to 50 centimeters; our 25 centimeters will not create problems for such equipment. It is very important - unquestioningly follow the safety rules recommended by the manufacturer; as soon as uncharacteristic sounds or vibrations appear, stop work immediately. If you hit a stone, you will have to move the location of the pile a little. Stones are often found in the Non-Black Earth regions of the Russian Federation; they were once “dragged” by glaciers.
Step 2. Insert casing pipes into the holes and check their vertical position. You need to check in several planes around the circumference. A very important point is that you need to consider options for fixing the pipes in a vertical position. You can support them with stops made of boards, you can put pads between the pipe and the wall of the hole in the ground. The main condition is that the piles must remain in this position until the work is completed, regardless of rain and wind.
Step 3 Insert two or three bars of construction reinforcement of a periodic profile into the pipes.
It will not work on compression, but only on tension. With its help, the risks of pile cracking from horizontal loads that occur during uneven freezing of the ground or its movements are eliminated. Make sure that the fittings do not touch the walls of the pipe; the distance between the wall and the fittings should be at least five centimeters. Only this thickness of concrete ensures its operation in a single structure with concrete.
To fill a pipe, you need to make concrete more liquid than for pouring strip foundation. At the same time, increase the amount of cement. If for ordinary concrete you can give two shovels of sand and three shovels of crushed stone per cent shovel, then in this case, for the same amount of sand and crushed stone, give two shovels of cement.
The pipe has a small diameter; an air lock in concrete with a diameter of 5 cm in our case reduces the cross-sectional area of the concrete pile by 2.5%. And this is only one plug, but what if there are several of them? The ideal option is to tamp the concrete with an electric vibrator. But only professional builders have them; everyone else has to use ordinary “pushes”.
Step 4. Once again we draw your attention to the strength of the pile fastening in a vertical position. Everything is normal - start filling the space between the casing pipe and the hole with soil. Sprinkle the soil in layers, each layer no more than twenty centimeters. Work evenly around the circumference, compact the layers using any available means. Constantly check the position of the pipe.
Fresh soil is never compacted manually to the required values; there will always be uneven shrinkage, which causes an increase in lateral loads. As a result, the piles may tilt. There is a simple way to minimize such risks. After each layer of compacted earth, a little concrete should be thrown into the cracks, the height of the concrete is approximately 10 centimeters. Throw it around the circle, make several such layers. A little concrete will be needed, but the stability of the pile will be ensured. When cut, you should end up with a layer cake. Concreting can only be done in two places - near the lower end of the pile or immediately at the bottom of the pit and near the upper surface of the earth. The average concrete belt works ineffectively. But if there is any concrete left, it is better to use it to fill the gap than to throw it away altogether.
Step 5 Using the same technology, fill all casing pipes with concrete. Everything is ready - stop work for at least two weeks. The pipes should be thirty to forty centimeters above ground level.
Step 6 After the concrete has hardened, you need to level the height of all piles. To do this, use a hydraulic level to make marks on the corner piles of the foundation. Taking into account the marks, draw lines around the entire circumference of the pipes. You need to cut off the remaining parts with a powerful grinder with a special disk. The disc must cut not only concrete, but also reinforcement. The tool can be purchased in specialized stores, however, it is quite expensive.
Stretch a rope between the cut end piles and make marks on all remaining piles. The rope can be removed; cutting off the ends of the piles is done using the same technology. The piles are approximately thirty centimeters high; at such a height it is very inconvenient to work with a heavy grinder. You will have to cut while lying down, prepare a place to lie down. Be sure to use safety glasses, and it is advisable to have a simple respiratory mask. When sawing concrete, a lot of dust appears, and cement dust has a very negative effect on the lungs.
There is no need to try to cut off the entire pipe in one pass; it is much easier to cut it around the circumference. Work slowly; the area for the grillage should be level and as horizontal as possible. If you don’t learn this way, you’ll have to level it with concrete. This is difficult to do; it requires a lot of practice in performing construction work.
The piles are sorted out, the concrete is “ripe” and you can start building the grillage.
Motor drill prices
Grillage
We have already said that we propose to make a grillage from a channel. We need to talk a little about channels, this will make it easier right choice. Specifications channels are prescribed in GOST 8240-89.
GOST 8240-89. Hot-rolled steel channels. Assortment. This standard establishes a range of channels with sloped internal flange edges and channels with parallel flange edges. File for download
The document provides classification and assortment.
You need to know two main differences on which the reliability and stability of the grillage depends. The fact is that the side shelves of the channel can be located at an angle or perpendicular to the wall.
This means that with the same values of the outer side of the wall, it has a different width on the side where the shelves adjoin. If the shelves are at an angle, then the internal width is reduced; you need to take a larger channel. For example, if for a pipe with a diameter of 200 mm it is enough to take channel number 22 with perpendicular flanges, then with corner shelves you need to take channel number 24. It is very important that the pile has a stop along the entire circumference, and not just at several points.
Take the exact distances between the corner piles, estimate the number of linear meters of rolled metal and cut the metal to size. It is highly desirable that the welding points do not sag; try to do them above the piles. At the corners, two touching pieces of channels are cut at an angle of 45° and welded.
Check the weld seams for quality; removing protruding parts with a grinder is not recommended. This can only reduce the strength of the connection; for the lower strapping row of beams, protruding seams do not have any negative effect. Between the metal and the wood, be sure to place roofing felt in two layers.
Video - Channel installation
Drilling wells for piles is an auxiliary technology for the construction of pile foundations in hard and non-cohesive, moisture-saturated soils, the implementation of which significantly increases the productivity of immersion reinforced concrete piles.
The company "Installing Pile" provides services for drilling wells for piles (Leader drilling). To carry out the work, we use a modern BM-811 installation, which has high drilling productivity for all types of soil common in the Moscow region.
This page provides information on the technology of drilling wells for piles. You will learn what drilling methods exist and in what cases their implementation is necessary. We will look at drilling for cast-in-place and driven piles, and also get acquainted with the technology with which drilling work is carried out.
How to drill wells for piles
The construction of wells for piles is carried out using self-propelled drilling rigs, which are equipped with equipment that uses rotary rotary drilling technology - an auger column. In the process of deepening the drill string into the ground, the excavated soil rises to the surface of the well along the helical blades of the auger, after the well is developed to the design depth, the column is removed from the excavation in reverse motion, and the finished well is used for further purposes - for driving reinforced concrete piles or forming cast-in-place supports .Rice. 1.1
Features of drilling technology depend on the ground conditions in which the work is carried out. If drilling is carried out on soft soils, soil development is carried out with a standard auger drill, without additional reinforcements. When drilling high-density soil or soils with a large number of rocky inclusions, the auger column is equipped with a carbide tip - a chisel, which takes on the resistance of the soil and significantly increases the efficiency of drilling hard rock.
If it is necessary to develop non-cohesive soils with low density, which, during the construction of a well, crumble from the walls of the excavation to the bottom of the face, drilling is carried out using special solutions - bentonite, clay or polymer, injected into the well by means of a compressor through a special pipe.
Rice. 1.2
Important: the use of such solutions significantly increases drilling productivity - they minimize the frictional forces between the soil and the drill string, reduce the density of the soil under the drill tip, and wash the crumbled soil to the surface under pressure. The well is also further strengthened due to the solidification of the solution on its walls, which prevents further rock collapses.
Rice. 1.3
Pile drilling technology
The technology of drilling wells for piles is in demand in two cases - when it is necessary to drive driven piles in difficult conditions and when arranging driven supports.Drilling for driven piles is called leader drilling. Construction of leader wells is used in the following situations:
- When driving piles into high-density soils that have high resistance, which the pile cannot overcome under the influence of an impact hammer or vibratory driver;
- When driving piles into hard frozen soil;
- When driving piles into non-cohesive, moisture-saturated soils - swampy, silty soils and quicksand, the insufficient density of which does not allow accurate positioning of the driven pile and leads to its deviations from the axis required by the project;
- When driving reinforced concrete piles near existing buildings, in this case, leader wells allow you to avoid dynamic loads on nearby foundations that arise during the operation of a diesel hammer.
Rice. 1.4
Drilling for cast-in-place piles is carried out during the construction of pile foundations, in which unfinished materials are used as supports. reinforced concrete products industrial production, and the piles are formed directly in the ground at the construction site. The process of their arrangement consists of developing a well of the required dimensions, immersing a reinforcement cage into the well and filling the excavation with a concrete mixture, as a result of which a full-fledged reinforced concrete support is created in the ground.
Drilling for cast-in-place piles
When drilling for cast-in-place piles, wells are constructed, the dimensions of which correspond to the design dimensions - the depth and diameter of the support formed in the soil. The drilling itself is carried out under the protection of a casing pipe - a cylindrical steel structure, which is simultaneously used as formwork for pouring concrete and prevents it from entering the well. groundwater and crumbling of its walls.
Rice. 1.5
Important: Casing pipes are prefabricated structures that are built up as the well deepens. The length of one casing section can vary from 2 to 6 meters. The lower section is equipped with a rock-cutting tip with welded carbide teeth.
Rice. 1.6
The drilling technology for cast-in-place piles is implemented in the following sequence:
- The drilling rig is placed at the well site (the area is pre-marked) and drills to a depth of 2 meters;
- The drill string is lifted and the first section of casing is installed, after which the drill is inserted into the pipe and further development of the well is carried out;
- The immersion of the casing occurs due to the extraction of soil by the auger under its supporting end and the influence of pressing forces;
- In the process of deepening the well, sections of the casing pipe are systematically increased (they are provided with coupling or threaded connections);
- After deepening the well to the design level, the auger column is removed and the bottom of the bottom is cleaned by tamping, flushing with drilling fluid or blowing with compressed air;
- The reinforcement cage is slinged, lifted and lowered into the well using a jib crane;
- A concrete pipe is being installed, its lower part is placed at a distance of no more than 30 cm from the bottom of the well;
- A concrete mixture is pumped into the well through a pipe, and the pipe itself systematically rises as the well is filled with concrete;
- Upon completion of concreting, the casing pipe is removed from the well and the concrete is compacted by vibrating the mixture.
Rice. 1.7
Important: drilling for cast-in-place piles without the use of casing pipes is possible when working in stable soil, the fluidity coefficient of which does not exceed 0.5
Drilling technology for driven piles
The depth of the leader wells developed for subsequent driving of reinforced concrete piles should be 1-1.5 meters less than the length of the submerged structure. The diameter is 30-50 millimeters less than the cross-section of the pile trunk, depending on the density of the soil.
Rice. 1.8
Leader drilling technology consists of the following stages:
- Geodetic exploration of the soil is carried out, aimed at establishing the density of the deep layers of the soil. The final decision on the need for leader drilling is made during the process of test driving of piles, during which the effectiveness of the piling hammers used in a specific type of soil is determined;
- Based on the soil characteristics of the construction site and the requirements for the dimensions of the leader wells, drilling equipment suitable for the work is selected;
- The pile field is laid out and drilling points are marked on the site;
- Equipment is delivered to the site and wells of the dimensions required by the project are drilled;
- Driving piles into leader wells is carried out sequentially by drilling them, since when a diesel hammer operates near an uncovered well, a collapse of its walls may occur;
Rice. 1.9
Important: to implement the leader drilling method, it is preferable to use drilling and piling rigs - multifunctional equipment that is equipped with attachments for drilling and driving piles, which allows you to do everything technological processes through one pile driver.
Drilling wells for driven piles - video
Video No. 1 - leader drilling for driving piles with a hydraulic hammer
Video No. 2 - drilling wells for driving piles with a diesel rod hammer
Video No. 3 - arrangement of a well and driving a pile using a drilling and piling machine
Technique used
Drilling wells for piles is carried out using MDR - mobile drilling rigs using rotary drilling technology. This equipment is equipped on the basis of wheeled vehicles or crawler excavators, which are equipped with appropriate drilling equipment.
Rice. 2.0
Depending on the technological design, MBUs are classified into:
- Solid auger drilling rigs equipped with an extendable drill string without an internal channel.
- Installations for CFA drilling, which use a drill string with an internal cavity through which drilling fluid or concrete mixture is injected into the well.
Important: solid auger drilling equipment is used to construct leader wells for driving piles; CFA drilling machines are used to create cast-in-place piles using the drilling injection method, in which concrete is pumped into the well immediately after it is driven.
Rice. 2.1
Modern MDRs are capable of drilling wells for piles to a depth of up to 50 m, which makes it possible to immerse composite piles of the maximum possible size into them; the drilling diameter varies from 100 to 800 mm.
Our drilling equipment
To drill leader wells and install cast-in-place piles, our company uses a wheeled drilling and piling machine BM-811. This is a productive technique that demonstrates high performance on all soils common in the central part of Russia, including frozen soil.Functionality of BM-811:
- Drilling wells to a depth of 12 meters, with a diameter from 150 to 450 mm;
- Implementation of inclined drilling with a slope from the vertical up to 90 0;
- Driving reinforced concrete piles weighing up to 3 tons and length up to 12 meters using a diesel hammer SP-75A (impact weight 1.2 tons).
Rice. 2.2
Important: BM-811 is distinguished by its high drilling speed - it drills a hole 8 m deep in frozen soil in 7-8 minutes.
Cost of work
- The company "Installation of Pile" offers its clients minimum prices in Moscow for drilling work - the price for drilling one linear meter of a well starts from 280 rubles.
- We are also ready to provide a highly productive drilling rig BM-811 for rent, the cost of which is 25 thousand rubles per day.
- Compare our prices with those of competitors and you will be convinced of the superiority of our pricing policy.
Order drilling for piles
If you are looking for a contractor who will drill for piles efficiently, quickly and inexpensively, use the services of our company. Call us at one of our contact numbers or fill out the form " Send a request"and our managers will contact you and offer Better conditions cooperation!Work on drilling wells for foundations is carried out both during the construction of buildings and structures, and during their reconstruction, as well as for strengthening. We solve problems of any type, regardless of their level of complexity.
The choice of equipment for drilling under foundation piles depends on a number of factors: the number of wells, their diameter and depth. We use a variety of drilling rigs that allow us to work both on large sites and in cramped conditions.
We have equipment for drilling under piles, which allows us not only to make wells, but also to install casing pipes in them. This makes it possible to save not only time, but also money, because you do not need to rent additional special equipment.
Our advantages
The MosSpetsTech company has extensive experience in creating wells for pile foundations. We:
- We offer favorable prices for our services;
- We provide well-maintained drilling rigs and experienced operators;
- We provide equipment on the day of your request;
- We promptly answer questions and help you choose rental equipment that is optimally suited for the tasks that need to be solved;
- if there is a need to remove asphalt or concrete pavement, we carry out the corresponding work using a hydraulic hammer;
- We work quickly and efficiently, at a time convenient for the customer, without weekends or holidays.
Basic information about the cost of our services is presented on this page of the site. The final cost is influenced by factors such as:
- distance of the object from the Moscow Ring Road;
- scope of work - number of holes, their depth and diameter.
To clarify prices and ask other questions, contact the managers of the MosSpetsTech company. Order a call on the website, and our employee will promptly contact you.
Contact us if you need high-quality drilling work.
Drilling wells for the foundation makes the construction of a building easier and faster. A pile foundation reduces construction costs and has a high load-bearing capacity. Due to their strength and reliability, piles are used in driving frame technology construction.
The main advantages of a pile foundation
The high load-bearing capacity of a pile foundation is in demand in industrial multi-storey and private buildings. The design diagram is used:
- for the construction of residential and industrial buildings;
- in areas with difficult terrain and significant elevation changes;
- when choosing frame construction technology.
Buildings on pile foundations are strong, reliable, and earthquake-resistant. In places with deep hard, load-bearing soil, another design for the load-bearing support of the building is impossible.
There is no seasonality of production. Work is carried out in all weather conditions; in winter, equipment and workers are not idle. Construction time is reduced.
- saves concrete, consumables, and labor costs for excavation work;
- increases the service life of the building;
- accelerates the commissioning of finished products;
- allows you to build on weak, floating soils;
- increases the strength and stability of buildings in areas with high seismic activity;
- reduces the cost of constructing a building and the total cost per square meter.
Pile-screw foundation
Buildings built according to such projects do not have a basement, so engineering equipment is located in attics and technical floors. Heating and hot water supply systems have overhead wiring.
Situations when it is necessary to drill wells for the foundation
Pile foundations are installed when there is a large load on the foundation, and in all cases when large-scale construction of sites is impossible under existing conditions. Obstacles to the development of a pit for other structural foundation schemes are natural conditions, changes in the terrain of the site, and the shallow occurrence of groundwater.
In permafrost areas of the Far North, foundations on piles are the only design solution for construction. The calculated depth of well drilling is taken below the freezing point of the soil in a given area.
In addition to geological features, the performance of work is influenced by artificial factors. These include the passage of underground communications under the construction site and development on a limited area within the block.
The depth of the pile foundation is calculated separately for each geographical area. Well drilling is used in conditions that technically do not allow the use of mechanical pile driving, using bored technology. The verticality of pile driving is affected by the remains of a demolished building in the rock layers, construction waste, and sand.
Vibration destroys neighboring engineering structures and moves the soil. Ready-made holes for installing piles reduce the impact of vibration on the surface, structures and communications located in the construction site area.
Necessary equipment for drilling wells
Drilling equipment, devices and equipment are conventionally classified into three types:
- Drilling tools, hand and mechanized. The auger is driven by a person or a motor.
- Drilling rigs. Auger drilling equipment and driving drive assembled on a metal welded frame.
- mounted on wheels or tracks.
Hand tools are used in private low-rise buildings and are limited to a hole diameter of 300 mm. Manual drilling of holes in dense, heavy soils is ineffective. Mechanized tools are designed to perform work up to 2 meters deep. The mechanism is driven by an electric motor or hydraulic motor. Frame installations allow you to drill holes up to 4 m deep and up to 320 mm in diameter. The composite auger drill is increased as it goes deeper.
Self-propelled drilling rigs are used in multi-story, industrial construction. Installations of high power and high productivity equally accurately perform vertical drilling of the horizon and work at an angle. under the foundation is in demand when there is horizontal displacement of the soil. Inclined piles are found in the foundations of bridges, power line poles, and port facilities. The average depth of foundation holes for self-propelled units is 8–15 m, which is sufficient for complex and permafrost soils. Complex machine mechanisms capable of not only drilling soil, but also driving piles are widely used.
Manual drilling
Drilling a hole for a foundation pile manually is a physically difficult and time-consuming process that makes sense only for small volumes and shallow depths of the holes. Used on clayey, heaving soils. The resistance of dense soil is difficult to overcome; it is difficult to maintain the verticality of drilling a hole. Hand tools They work together, the efforts of one person are ineffective.
TISE drills are widely used in private housing construction. The abbreviation TISE stands for “Technology of Individual Construction and Ecology.” The drill is distinguished by a structural solution that makes it possible to obtain underground expansion. The expansion increases the support area and load-bearing capacity of the pile. When drilling for the foundation, the earth is cut with edges and raised to the surface.
Power tools reduce labor costs. The main thing in the process is to keep the drill in a strictly vertical position. To carry out the work, 2 people are required. Motor drills run on gasoline, a mixture of gasoline and oil. Electric earth drills operate from the mains, have insufficient power, the motor overheats under the load, and therefore are not used in foundation construction.
Types of foundation drilling
Well drilling methods are classified into 3 categories.
Leader. The technology consists of using drilling before immersing the pile to eliminate vibration and ensure the verticality of the element.
Bored. According to the technology, a reinforcing frame is installed in the drilled hole, concrete is poured with a hose in layers of 30 cm, air is released and compacted.
Buroinjection. It differs from bored vertical drilling in the method of concreting. The concrete solution is fed through a hollow screw under pressure.
Drilling with casing
Drilling technology with casing protection is used in conditions of dense buildings and horizontal ground movement. The casing maintains the pressure of the rock, preventing the walls from crumbling, moving, or filling the hole.
During the drilling process, the pipe is immersed into the finished tunnel in sections fastened together by welding or special clamps. After completion of the process, the pipe is dismantled or remains in the design position, filled with concrete mixture and, after hardening, becomes a single whole. The method of driving the casing is called rotary or drilling. The rock destroyed by the surface of the auger column is brought to the surface by a steel spiral, or flange.
Casing pipes are made from the following materials:
- alloy and carbon steels;
- polypropylene;
- asbestos cement;
- plastic.
The casing experiences tension and internal and external pressure. The pipe material must effectively withstand these loads.