Modern building technologies use reinforced concrete piles as the basis of various structures very widely. They are used in the construction:

• multi-storey residential buildings;
• factory buildings and shopping centers;
• bridges and flyovers;
• aboveground pipelines.

Prefabricated piles are driven into the ground in several ways - vibration immersion, driving, screwing, combined effects. They dive from 2-3 to 28-30 meters, depending on the characteristics of the soil.

The second type of piles - bored, is a drilled hole in which a metal reinforcing frame is installed and this entire structure is filled with concrete. The depth of such a pile can reach 40 meters. In stable dense soils, concrete is poured directly into the drilled well, in unstable and highly watered soils - into a special metal pipe called casing.

Depending on the characteristics of the soil and the characteristics of the equipment used to drive or install the piles, some part of it remains above the ground - the head, protruding to a height of 1-3 m. But further construction can be continued only if all the piles are cut at the same height. Cutting pile heads is a laborious and technically complex process that takes a lot of time.

Modern technologies for leveling the heads of reinforced concrete piles

The RezMaster company has at its disposal modern equipment that allows cutting pile heads at a speed of up to 100-120 driven piles and several dozen bored piles. Pile felling is carried out using hydraulic equipment mounted on an excavator boom equipped with a dual-circuit hydraulic system.

Pile breakers are mounted tools that are installed instead of the excavator bucket or in parallel with it. In the second case, the bucket is a non-working part of the hitch. The design of the head cutting equipment consists of hydraulic cylinders located on a round base, acting on the movable inner part. When the cylinders are turned on, the cutting segments move to the center of the circle and destroy the concrete by squeezing with great force.

In this action, only concrete is destroyed - the reinforcement remains intact and, after the removal of concrete fragments, it is used as an integral part of the building's welded frames, grillage elements, or for other technological purposes. Removal of concrete is carried out by lifting the tool vertically upwards and practically does not require manual labor.

The company "RezMaster" performs work on cutting the heads of reinforced concrete piles of any kind. It should be noted that during this operation there are no shock loads and the strength of the structure is not reduced, there is no noise, so the work can be performed at any time of the day.

Prices for cutting piles

The prices for cutting piles are designed taking into account the hardness of the material, the size and type of supports, as follows:

• for square driven piles - from 400 rubles / piece;
• for round bored piles - from 1200 rubles / piece.

In each case, the cost of work is calculated separately, taking into account both the features of the object and the possibility of providing discounts. All the necessary information can be obtained on the website, by phone or at the office of RezMaster

*We never have low-quality projects of pile foundations. We fully monitor and implement all design decisions. Our work fully complies with the requirements of the code of design and construction rules, as well as the rules for designing foundations.

Cost of work

Why cut pile heads?

Procedure pile driving both by driving method and by vibration immersion methods or static indentation does not often end at a given depth. The criterion for the end of the immersion process is usually a given failure of the pile, i.e., the magnitude of the immersion as a result of several impacts or at the end of a certain time period during vibration or static indentation. If the specified failure is not achieved, then this means that the pile does not have the required degree of soil resistance.

Therefore, under the subsequently applied load, it will fall further into the ground and a significant part of its load will be redistributed to neighboring piles. Failure to achieve a given failure forces one more pile to be added to the driven pile and to drive or press the first one even deeper. The not driven rest of the second pile must be removed, leaving the upper parts of the piles sticking out of the ground only not above a certain level.

If, when the pile is driven, the specified failure occurs, and the pile sticks out several meters above the specified level, then it must also be cut off and later on, or leader drilling or reduce the length of the piles.

If there is already a failure, and a small unfinished section of the pile remains, then they continue to hammer it to the desired level (if it works out).

Sometimes it is not the second pile that is driven in, but another pile is driven next to the underloaded one. According to the theory of pile driving, it is believed that around a clogged reinforced concrete pile, the soil is compacted at a distance of 2.5–5 times its cross section. For example, during the construction of the foundation of St. Isaac's Cathedral in St. Petersburg, the soil could be removed from the gap between the piles driven in only after it was beaten off with a pickaxe or crowbar. But they were actually built on a swamp, and more than 16 thousand wooden piles made of pine and larch were hammered.

Equipment and technology for cutting pile heads according to SNiP

After the pile driving is completed, the construction site looks like a palisade of piles of different lengths sticking out of the ground.

Cut them down in different ways. The most common of them are:

1. Manual cutting. It is used in cases where you need to cut down several piles, for example, when building a private house. Use a large chisel with welded handles and a sledgehammer or hammer. The concrete is broken and the reinforcement is released, which is then cut off with a gas cutter or a cutting wheel.

2. Jackhammer. They are used on construction sites with several dozen shortened piles. To work with a jackhammer you need:

The jackhammer itself is electric or pneumatic;

Special interchangeable concrete-breaking peaks;

Stationary or mobile compressor.

Manual fluffing and felling of piles - video

Disadvantages:

High labor costs;

Low speed of work;

Vibrations and noise from the operation of the hammer, the process itself and the operation of the compressor;

Some of the reinforcing bars may be damaged or even cut;

The formation of cracks in the concrete of the pile is possible.

3. Cutting with a special hydraulic mechanism.

The use of a traditional hydraulic hammer, which is used to break rock, often leads to the appearance of longitudinal cracks of great length. This is because the hydraulic hammer strikes with its lance usually from top to bottom, i.e. along the power reinforcement of the pile and pushes the pile reinforcing bars out of the pile structure. Therefore, this method is rarely used and will probably cease to be used in the coming years.

The use of a special hydraulic mechanism is the most productive and easy to operate.

Required for work:

Hydraulic cutter with chopping mechanism;

Crane or excavator provided with elements for mounting attachments;

Standard hydraulic system of excavator or crane.

How are hydraulic pile head cutters arranged?

This kind of hydraulic cutters have several types of design:

BUT. For reinforced concrete piles with a square cross section. A square frame is made, on the sides of which hydraulic cylinders are fixed. High-strength cutting elements are fixed on the piston rods moving in this cylinder. Their power edges, which split the concrete, go inside the power frame and are located horizontally and in the same plane. The hydraulic system connects all cylinders with high pressure pipelines and is connected to the hydraulic system of the base carrier, such as an excavator.

The frame is put on the cut pile with the help of a lifting mechanism and lowered to the desired height, i.e., to the place of felling. Turn on the hydraulic fluid supply. The hydraulic cylinder rods push the cutters inside the frame and break off the top of the pile head. After that, the frame is raised by 100 - 150 mm and the second split of the concrete is made. The crumbled pieces of concrete spill out and expose the reinforcement. If its bare part about the project is enough, then the process is over. If not enough, repeat until the desired length is obtained.

Cutting piles with hydraulic shears - video

B. For round piles, the frame is made round. Cylinders with cutters are fixed in the right quantity. For cutting piles of large diameter, for example, 1,000 - 1,800 mm, there may be a dozen or even several dozen.

There are a lot of manufacturers and varieties of structures for this purpose, as well as their technical capabilities. But all of them speed up the process of cutting pile heads tenfold compared to manual cutting of the unnecessary end of the pile.

TYPICAL TECHNOLOGICAL CHART (TTK)

FELLING "HEALTHS" OF REINFORCED CONCRETE SOLID PILES OF SOLID SQUARE SECTION

I. SCOPE

I. SCOPE

1.1. A typical technological map (hereinafter referred to as TTK) is a comprehensive organizational and technological document developed on the basis of methods of scientific organization of labor intended for use in the development of Work Production Projects (PPR), Construction Organization Projects (POS) and other organizational and technological documentation in construction.

TTC can be used for the proper organization of labor at a construction site, determining the composition of production operations, the most modern means of mechanization and methods for performing work according to a specific technology.

The TTK is an integral part of the Work Execution Projects (hereinafter referred to as the PPR) and is used as part of the PPR in accordance with MDS 12-81.2007.

1.2. This TTK provides instructions on the organization and technology of work on felling the "heads" of reinforced concrete piles with a cross section of 350350 mm by 0.65 m, followed by exposing reinforcing bars for embedding them into a headboard when constructing a pile foundation in an embankment of subgrade.

The composition of production operations, requirements for quality control and acceptance of work, planned labor intensity of work, labor, production and material resources, measures for industrial safety and labor protection were determined.

1.3. The regulatory framework for the development of a technological map are:

Standard drawings;

Building codes and regulations (SNiP, SN, SP);

Factory instructions and specifications (TU);

Norms and prices for construction and installation works (GESN-2001 ENiR);

Production norms for the consumption of materials (NPRM);

Local progressive rates and rates, labor costs rates, material and technical resources consumption rates.

1.4. The purpose of creating the TTC is to describe solutions for the organization and technology of work on felling the "heads" of reinforced concrete piles with a cross section of 350350 mm by 0.65 m, followed by exposing reinforcing bars for embedding them in a headboard when arranging a pile foundation in an earth bed embankment, in order to ensure their high quality, as well as:

Reducing the cost of work;

Reducing the duration of construction;

Ensuring the safety of work performed;

Organization of rhythmic work;

Rational use of labor resources and machines;

Unification of technological solutions.

1.5. On the basis of the TTK, as part of the PPR (as mandatory components of the Work Execution Project), Working Technological Charts (RTK) are developed for the performance of certain types of work (SNiP 3.01.01-85 * "Organization of construction production") for felling the "heads" of reinforced concrete piles with a section of 350350 mm by 0.65 m, followed by exposing the reinforcing bars for embedding them into a cap when arranging a pile foundation in an earth bed embankment.

The design features of their implementation are decided in each case by the Working Design. The composition and level of detail of materials developed in the RTK are established by the relevant contracting construction organization, based on the specifics and scope of work performed.

RTK are considered and approved as part of the PPR by the head of the General Contractor Construction Organization.

1.6. TTK can be tied to a specific object and construction conditions. This process consists in clarifying the scope of work, means of mechanization, the need for labor and material and technical resources.

The procedure for linking the TTK to local conditions:

Consideration of map materials and selection of the desired option;

Verification of the conformity of the initial data (volumes of work, time standards, brands and types of mechanisms, building materials used, composition of the link of workers) to the accepted option;

Adjustment of the scope of work in accordance with the chosen option for the production of work and a specific design solution;

Recalculation of costing, technical and economic indicators, the need for machines, mechanisms, tools and material and technical resources in relation to the chosen option;

Registration of the graphic part with a specific binding of mechanisms, equipment and devices in accordance with their actual dimensions.

1.7. A typical flow chart has been developed for new construction and is intended for engineering and technical workers (work foremen, foremen) and road construction workers performing work in the II road-climatic zone, in order to familiarize (train) them with the rules for the production of work felling the "heads" of reinforced concrete piles with a cross section of 350-350 mm by 0.65 m, followed by exposing the reinforcing bars for embedding them into a cap when arranging a pile foundation in an earth bed embankment using the most modern means of mechanization, progressive designs and methods of performing work.

The technological map has been developed for the following scopes of work:

Highway - III category;

The length of the subgrade reinforcement section - L=800.0 m;

Pile volume - V = 2200.0 m .

II. GENERAL PROVISIONS

2.1. The technological map was developed for a set of works on felling the "heads" of reinforced concrete piles with a cross section of 350350 mm by 0.65 m, followed by exposing reinforcing bars for embedding them into a headboard when constructing a pile foundation in an earth bed embankment.

2.2. The work on felling the "heads" of reinforced concrete piles with a cross section of 350350 mm by 0.65 m, followed by exposing the reinforcing bars for embedding them into a cap when arranging a pile foundation in a subgrade embankment, is carried out by a mechanized team in one shift, the working time during the shift is:

2.3. The scope of work performed sequentially when felling the "heads" of reinforced concrete piles with a cross section of 350-350 mm by 0.65 m, followed by exposing the reinforcing bars to embed them into a cap when constructing a pile foundation in an earth bed embankment, includes the following technological operations:

Geodetic marking of places for felling heads on piles;

felling pile heads;

Exposing reinforcing bars of piles.

2.4. The technological map provides for the performance of work by an integrated mechanized unit consisting of: bulldozer B170M1.03VR (=4.28 m, =1.31 m); truck jib crane KS-45717 (carrying capacity Q=25 t); Atlas Copco XAS 97 Dd mobile compressor ( P=5.3 m/h, =0.7 MPa, m=940 kg); jackhammer M0-2K (weight m=10 kg, =0.5 MPa, impact frequency 1600 beats/min); injection gas burner Р2А-01 designed for oxy-acetylene cutting, the scope of supply includes inner and outer mouthpieces, interchangeable mouthpieces, wrench, o-rings, gas cylinders and reducers.

Fig.1. Cargo characteristics of the automobile jib crane KS-45717

Fig.5. Injection gas burner Р2А-01

A - burner; b - injection device; 1 - mouthpiece; 2 - mouthpiece nipple; 3 - tip; 4 - tubular mouthpiece; 5 - mixing chamber; 6 - rubber ring; 7 - injector; 8 - union nut; 9 - acetylene valve; 10 - fitting; 11 - union nut; 12 - hose nipple; 13 - tube; 14 - handle; 15 - gland packing; 16 - oxygen valve.*

Fig.6. Gas cylinders and reducers

A - oxygen cylinder, volume 6 m; b - acetylene cylinder, volume 5.32 m; g - oxygen reducer; e - acetylene reducer.

2.5. For cutting pile heads are used technical gaseous oxygen meeting the requirements of GOST 5583-78; acetylene technical gaseous meeting the requirements of GOST 5457-75.

2.6. Felling of the heads of reinforced concrete piles should be carried out in accordance with the requirements of the following regulatory documents:

III. ORGANIZATION AND TECHNOLOGY OF WORK PERFORMANCE

Obtain from the technical Customer (developer) the Certificate of selection of a land plot for the construction of an object, approved by the decision of a local government body or an executive body of state power of a constituent entity of the Russian Federation;

At least 10 days before the start of construction work, receive from the technical Customer (developer) the working documentation for the geodetic staking base and the points of the geodetic base fixed at the construction site with the preparation of the Certificate of Inspection of the geodetic staking base of the capital construction object, in the form given in Appendix 1 , RD-11-02-2006;

Solve the main issues related to the logistics of construction, incl. conclusion of contracts for the supply of material and technical resources, placement of orders for the manufacture of elements of prefabricated structures, parts and products necessary for the construction of an object (structure);

Obtain from the construction control of the Customer the main sets of working drawings with the inscription " In production works "and provide them with a construction site;

Obtain from the Customer's construction control Technical documentation for driving and testing test piles, indicating their types, length and bearing capacity;

Organize a thorough study of design materials containing the initial data for construction by craftsmen and foremen;

Develop a design plan for the "Pile foundation device with a flexible grillage to eliminate subgrade subsidence on a road section", containing decisions on the organization of construction production, road construction technology, coordinate them with the General Contractor and the Customer's construction control;

Appoint, by order of the construction organization, persons responsible for the safe production of work, control and quality of their implementation;

To equip the brigade (link) with workers of relevant professions and machinists of road-building machines with the necessary qualifications;

Familiarize the foremen and link officers with the Project for the production of work, Technological maps and the technology for the production of work, as well as issue to the teams and links Work orders, Calculations and Limit-fence cards for materials for the entire volume of assigned work;

The task order indicates the types of work performed in this area, their volume, production rates, the required amount of working time to complete the entire scope of work, the amount of piecework earnings. It also stipulates the conditions for bonuses to the workers of the brigade;

To instruct members of teams (links) on industrial safety and labor protection during the performance of work;

Provide workers with personal protective equipment;

Establish temporary inventory household premises for storing building materials, tools, inventory, heating workers, eating, drying and storing work clothes, bathrooms, etc.;

Develop schemes and arrange temporary access roads for traffic to the work site;

Arrange temporary storage areas for receiving structures, building parts and materials;

Prepare machines, mechanisms and equipment for the production of work, deliver them to the facility, mount and test them at idle;

Deliver to the work area the necessary equipment, devices for safe work performance, electrified, mechanized and hand tools;

Provide the construction site with fire-fighting equipment and signaling equipment;

Provide communication for operational dispatch control of the production of works.

3.3. General requirements for the performance of work

3.3.1. In order to increase the stability or accelerate the settlement of subgrade embankments and reduce the effect of dynamic load on the structure, the following design and technological solutions are envisaged:

Construction of an embankment on a weak foundation with a calculated mode of backfilling, ensuring the stability of the structure during construction and operation;

The use of separating layers of geotextiles to prevent mixing of dumped soils and soils of a weak base;

The use of reinforcement elements from woven geotextiles or geogrids together with nonwoven geotextiles to ensure stability (base reinforcement);

Temporary surcharge device to accelerate the process of consolidation of soils of a weak foundation;

Construction of "light" foam embankments to create stable and sediment-free embankments;

Vertical drains made of sand, discrete materials, special (volumetric) geocellular materials in order to accelerate the settlement of a weak base;

Installation of piles from sand, crushed stone, cement soil, reinforced concrete (driven piles), cement soil reinforced by jet technology, injection piles with a grillage of geocellular materials or woven geotextiles in order to create stable or sediment-free structures.

3.3.2. embankment base- a natural massif of soil, located below the body of the embankment.

3.3.3. mound- an earthen structure made of bulk soil, located above the natural level of the earth.

3.3.4. The device of pile foundations from reinforced concrete driven piles includes the following technological operations:

Preparation of the base surface;

Marking works;

Backfilling of the working platform from local soil (if necessary). The width of the working platform must exceed the width of the pile field by at least 2.5 m;

Drilling leader wells of a given diameter and depth;

Driving piles into leader wells. Piles are arranged flush with the surface of the working platform or with a slight excess above it. Piles are driven to failure using standard equipment;

Above the driven piles, caps of a design configuration made of monolithic concrete are arranged;

A leveling layer of sand no more than 0.2 m is poured over the headbands;

A flexible grillage of geosynthetic sheets is arranged along the leveling layer;

On top of the grillage, the subgrade is dumped with layer-by-layer compaction.

3.3.5. When arranging embankments on all types of pile foundations, the thickness of the working platform, depending on the bearing capacity of the foundation soil and the weight of the mechanisms used, must be at least 0.75 m. The width of the working platform must exceed the width of the pile field by at least 2.5 m.

3.3.6. working platform- the lower part of the embankment being poured on the thickness of the weak soil, which should ensure the patency during the construction of construction vehicles or the possibility of temporary location of the equipment necessary for the construction of the embankment of the design height.

3.4. Preparatory work

3.4.1. Prior to the felling of the pile heads, the preparatory work provided for by the TTC must be fully completed, including the following operations and processes:

Completed pile driving in this pile field;

Issued by the act in the prescribed manner, the delivery and acceptance of the section of the pile field;

The availability of design and estimate documentation was checked and the familiarization of engineers and workers with the working drawings of the pile field and the Pile Works Project;

The design marks of the cut on the piles have been applied;

The places of storage of cut "heads" of piles and their places of loading are determined.

3.4.2. Felling of the heads of driven piles is allowed after the acceptance of the pile field by the representative of architectural supervision, and drawn up by the relevant act.

3.4.3. The completed work on driving the pile field into the base of the embankment of the subgrade of the highway must be documented by the Certificate of Inspection of Critical Structures in accordance with Appendix 4, RD-11-02-2006, signed by the representative of the technical supervision of the Customer.

3.4.4. The transfer of the geodetic mark to each pile is carried out using digital level Sokkia SDL50 from a cast-off located along the perimeter of the pit. Geodetic sign (reper in the form of a pencil line on the side surface of the "head" of the pile) determines the height position of the pile relative to the level of the grillage. The mark of the driven pile head is 0.70 m above the mark of the bottom of the cap, and the mark of the felling of the pile heads should be 0.65 m. 0,000 the mark of the cap was adopted, corresponding to the absolute mark available in the Working Draft (see Fig. 7).

Today it is impossible to imagine construction without the use of pile structures, which are reinforced concrete products with a reinforcing cage. However, regardless of how accurate their installation was, the felling of piles is mandatory, which is necessary to form the basis for fasteners and give all parts the same length.

Three ways of cutting piles

Modern construction provides for three options for felling piles. Their use depends entirely on the type of planned work and how appropriate this or that technology is in relation to them.

We will look at all three technologies, learn about their advantages and disadvantages.

Manual punching

This technology is performed using a special tool - a jackhammer and scissors. It is worth noting that hydraulic shears provide a high-quality cut and speed of work, but it has a rather high cost. To date, this method is used quite rarely due to the high labor costs.

Stages of felling pile heads with a jackhammer

First of all, the line is marked along which the support will be cut. With the help of a hammer, a furrow is outlined. Concrete is broken off with a special technique from top to bottom or from bottom to top. The reinforcement cage remains intact. The reinforcement is cut and then connected to the grillage structure.

Advantages and disadvantages:

• The only advantage of this method is its low cost.
• There are much more disadvantages: the method is rather slow - only about 12 piles can be cut in one shift, and during further construction, the reinforcement cage is often destroyed, and, as a result, the entire pile is unusable.

Cutting with hydraulic shears is as follows

According to the intended cut level, a special nozzle in the form of a ring is put on. Then, with the help of the cutting part of the tool, pieces of concrete are carefully bitten off so that the reinforcement cage remains intact. A reinforcing bar is cut, its fastening to the grillage.

Advantages and disadvantages:

• Pros: a much better cut than in the case of a jackhammer, the structure will definitely remain intact and intact. In addition, the work is carried out quickly - only 5-10 minutes per pile.
• Cons: high cost of the tool.

When choosing a manual cutting method, we strongly recommend that you still invest in hydraulic shears. Be sure: restoring piles after a jackhammer will cost you much more.

We cut piles with cutting mills

This method is also not very popular and is gradually falling out of use, since cutting equipment requires a very accurate calculation and appropriate selection of cutters.

However, if the equipment is properly selected, pile cutting is fast and has a high cut quality. In addition, the cutter can be attached to the excavator and if the specialist who controls the equipment has the necessary skills, the cut is performed accurately and does not damage the reinforcing cage.

An important point: the outer diameter of the cutting cutter must be less than the cross section of the reinforcing structure .

On the video: Cutting the pile head

Best Choice - Hydraulics

Pile cutting using mounted hydraulic equipment has become widespread in construction due to its versatility and ease of use at any construction site. Also, the attachment of equipment can be made to a tractor or excavator.

The principle of operation of hydraulic technology is as follows: pistons arranged in a circle synchronously and evenly chip concrete. Thus, this scheme assumes a smooth, accurate felling, excluding any damage and destruction of concrete and reinforcing cage.

An important point: the choice of equipment depends on the size of the pile and the design of the reinforcing cage, but there are also universal devices that fit almost all options. Only the right tool will allow you to do the job as efficiently and quickly as possible.

Today, we have reviewed all known cutting methods, what technologies are used and what results each of them brings. And it's up to you to choose the best solution.