Centrifuged piles are used in power transmission line foundations.
Centrifuged piles have a diameter of 42 and 56 cm. In long formwork, several pile links - pile trunks - are made simultaneously. For the manufacture of piles with a diameter of 0.42 m, formworks 20 and 24 m long are used, and in each formwork a pile blank is made, including from 6 to 2 pile links of equal length, used as driven shafts, as well as screw piles, the links have 3 types of reinforcement.
To manufacture piles with a diameter of 0.56 m, formworks of standardized racks of reinforced concrete supports with a length of 22.2 and 26.4 m are used, and in each formwork a pile blank is made, including 2 or 3 links of the same length. The links have 2 types of reinforcement. Piles are assembled from pile links and caps welded to them on top and tips on the bottom.
The structures are made of heavy concrete with compressive strength class B40. The grade of concrete for frost resistance is not lower than F150, for water resistance W6. The grade of concrete for piles used in areas with a design temperature below minus 40C should be used for frost resistance not lower than F200, for water resistance W8.
As longitudinal reinforcement for centrifuged piles, hot-rolled steel of class A-V in accordance with GOST 5781-82 grade 23Х2Г2Т is used for welded structures made of steel in accordance with GOST 19281-73, GOST 19282-73.
Hot-rolled reinforcing steel rods of class A-I are used in accordance with GOST 5781-82 and GOST 380-71. The spiral is used from ordinary reinforcing wire of a periodic profile of class BP-I in accordance with GOST 6727-80 and GOST 380-71.
Mounting loops of structures should be made of smooth hot-rolled reinforcing steel rods of class A-I grades VSt3ps2 and VSt3sp2 in accordance with GOST 5781-82. Steel grade VSt3ps2 is not allowed to be used for mounting loops in piles intended for lifting and installation at air temperatures below minus 40C.
Welded reinforcement and embedded parts must meet the requirements of GOST 10922-75. Anchor bolts (studs) should be used from steel grade VSt3sp2 in accordance with GOST 380-71.
These products meet the requirements of the current standard series 3.407.9-146
Product labeling is adopted in alphanumeric groups:
Example: TS 42.10-1where,
CS – centrifuged pile;
42 – diameter, cm;
10 – length, m;
1 – first type of reinforcement.
Products should be stored in stacks in horizontal rows in a specialized room. When stacking, spacers must be placed between the horizontal rows of piles to ensure the stability of the stack. When loading and unloading, damage to the piles should be avoided, as well as dragging them along the ground. When transporting, the speed limit must be observed. Warehousing and storage of structures is carried out in accordance with the requirements of GOST 13015.4 - 84 and SNiP III-4-80.
The centrifugation method is used to produce hollow round piles with a diameter of 0.4–0.8 m and shell piles with a diameter of up to 2 m and a length of 3 to 12 m. Reinforcement is performed with a welded cylindrical frame made of reinforcing rod and wire; the pouring material is special grades of concrete.
The production of centrifuged round piles is carried out on special equipment with a rotating collapsible cylindrical shape. A reinforcement frame is placed in the lower half of the form, and the upper part of the form is attached. After the rotation begins (speed 100–250 rpm), concrete is fed into the end holes of the mold, which is compacted on its side walls under the influence of centrifugal forces. After steaming and aging, the mold is disassembled. The finished pile is hollow inside, the wall thickness is 80 - 200 mm.
Hollow piles produced by centrifugation have a number of advantages compared to monolithic ones:
Centrifuged piles with a diameter of up to 0.6 m are immersed in the ground, covered at the bottom with a steel or reinforced concrete shoe. Shock and vibration methods are used to immerse them. With a diameter greater than 0.6 m, a pile driven with a closed end may collapse from excessive soil pressure on the side walls.
Piles with a diameter of more than 0.6 m are immersed open at the bottom, and the soil partially fills the internal cavity of the pile. In some cases, the soil from the internal cavity of the pile is removed during the immersion process, then a concrete mass is introduced into the resulting void. The low-frequency vibration method is used for immersion.
Driving large-diameter piles requires significant effort, so in these cases, especially powerful vibratory drivers are used, installed on the head of the pile, and the lower end of the pile is equipped with a steel ring knife welded to the reinforcement frame, which simplifies advancement in the ground.
If it is necessary to obtain a large shaft length, the piles are increased during the driving process with additional pile links, and welded and flange bolted connection methods are used.
Centrifuged piles
TsS 56-7-2 foundation elements used to impart sufficient rigidity and stability to power lines with rated voltages up to 55-500 kW. Products of this type structurally look like a round rod with a pointed end. The beveled part allows you to drive elements into the ground more easily and quickly. Fastening to power line posts is done using metal brackets. It is advisable to use these products in the construction of deep foundations, as this allows for significant savings in material.Centrifuged energy piles must meet the most stringent requirements for strength, rigidity, reliability and durability, so they are manufactured in accordance with the requirements of the standards
Series 3.407.9-146 . This ensures that the finished elements will easily cope with the pull-out and compressive loads for which they are designed. The selection of piles is carried out according to the specified parameters, taking into account a sufficient safety margin.1. Labeling options.
Designate centrifuged piles TsS 56-7-2 in accordance with the requirements of the standardSeries 3.407.9-146 . Markings are written in different ways, which in all cases is not incorrect spelling. Let's indicate them:
1. TsS 56.7.2;
2. TsS 56-7-2;
3. TsS 56-7.2.
2. Main scope of application.
Piles TsS 56-7-2 used in the construction industry in the field of energy. These are elements used to create reliable support for power transmission lines. It is important to use piles of this type on difficult soils, when soil conditions do not allow the installation of a structure without a foundation. It is optimal to use piles of this type for the construction of power lines in swampy areas, as well as in conditions of frozen or thawed soil. However, such reinforced concrete products are not suitable for round piles for silty, clayey, fluid, rocky, permafrost soils, and peat. Due to their high strength, the products can be used for a long time without investing in repairs and maintenance.
The main function is the transfer of perceived loads and their uniform distribution onto the natural foundation, thus creating a stable and reliable support for the engineering structure. Thanks to the increase in the support area, the power transmission line acquires a reliable and durable foundation. CS piles are used on “weak” and liquid soils in conjunction with one-size power transmission line posts, type VL. The driving is done either strictly vertically or at a slight angle to a depth of at least 3-4 meters to give greater strength and stability to the structure.
3. Marking designation.
Centrifuged piles
TsS 56-7-2 designated according to strict requirementsSeries 3.407.9-146 . The alphanumeric combination necessarily reflects the type of product and main dimensions. Numerical data is recorded in decimeters and rounded to a whole number for ease of writing and reading. MarkingTsS 56-7-2 means:1. C – centrifuged (method of making piles);
2. C – pile;
3. 56 – diameter, in dts.;
4. 7 – length, in m;
5. 2 – digital reinforcement index.
When using prestressed reinforcement, the marking is additionally marked with the designation N.
Marks are applied to one of the ends of the pile, often closer to the head, with black indelible paint. Additionally, information about the manufacturing company, the date of production of the batch of concrete products and the weight of the product are indicated.
Characteristics piles TsS 56-7-2 :
Length = 7000 ;
Diameter = 560 ;
Weight = 1840 ;
Volume of concrete = 0,7 ;
Geometric volume =2,1952 .
4. Basic characteristics of materials.
Manufacture centrifuged piles TsS 56-7-2 from heavy grade concrete with a strength class of at least B40. The material must also meet high standards for frost resistance (at least 150 freeze-thaw cycles), water resistance (grade W4) and crack resistance. The requirements are reflected in the current regulations. Operation of CS piles can be carried out at temperatures down to -40 degrees. The products are reinforced with wire of class A400 with prestressing (the rods are tensioned using an electrothermal method) and steel spirals of class A500. Embedded parts are used. All metal components undergo anti-corrosion treatment. It is necessary to create a concrete layer 18 mm thick above the reinforcement.
We produce high quality piles; shrinkage cracks with a thickness of more than 0.2 mm are not allowed on the surface. Centrifuged piles belong to reinforced concrete products, which are considered rare and specific. Thanks to the streamlined structure of the body, the technological margin of strength and resistance to complex natural phenomena increases. The support resists external factors and is not subject to deformation processes.
It is difficult for a customer who needs to buy piles to check the quality of reinforced concrete and production technology. Raw materials for the product must be prepared according to standards that ensure compliance with the technological process at all stages of production. In this case, we can only hope for the integrity of the manufacturer. We manufacture piles and sell them with a quality guarantee.
The buyer of centrifuged products has reason not to trust intermediaries who can resell piles from unknown manufacturers. Even the presence of a quality certificate does not provide confidence that the products are of high quality. In this regard, the price of piles also cannot be a criterion by which the strength of reinforced concrete products is determined.
Therefore, contacting us is the most correct way out of the situation when the customer wants to trust the supplier from the first transaction. We make piles of standard sizes and to order, if special types of structures are required, in accordance with non-standard projects. Concrete products are accompanied by metal embedded elements of a monolithic structure for fastening with grillages.
In production, centrifuged piles undergo quality control and testing. In addition to careful dosing of concrete mixtures, visual control of the output product, the racks are subject to test loads, as a result of which you can verify the original rigidity, stability and strength.
The sale of piles from the manufacturer guarantees a long service life of the product in high-quality condition without the threat of destruction of the reinforced concrete structure under the influence of weather and mechanical factors. Of great importance in the production of centrifuged piles is the use of a special concrete mold.
Conical racks or centrifuged piles for creating a foundation for power line supports are reinforced concrete products of increased strength with a pointed rod of round cross-section. They are driven into the ground with a special technical device. Thanks to the technology of installing foundations for supports, which does not require digging holes, installation work is carried out at a high pace, which increases the speed of laying electric highways.
Centrifuged piles are recommended for use with seismic activity up to nine points. The structure of the product assumes the integrity of the body during manufacture by pouring the mold with high-density concrete. To increase strength and withstand moisture and aggressive environmental factors, special additives are added to the composition of heavy concrete, and the body itself is reinforced with rods and meshes made of frost-resistant steel.
They are made of high quality concrete, their average density is 2200-2500 kg/m3. They are used as supports for power lines with a voltage of 35-750 kV. They can be used with environments that have an aggressive effect on reinforced concrete. The length of the racks is from 22 to 26 m.
The cylindrical rack is provided by the manufacturer for the racks of portals of open 220-330 kV metering devices, lightning rods, masts, etc. Cylindrical shaped poles are widely used in the normalization of various power lines, as well as on the electric railway as supports for communication lines.
To withstand very heavy loads from electrical wires, spatial system supports are used (for example, when the distance between the supports is 200-300m). All components of such supports are made by centrifugation. SCP racks (Cylindrical portal rack), traverses are combined using welding of iron clamp combinations to embedded parts.
Let's look at the decoding of supports using the example of the SCP Rack support (Cylindrical Portal Rack). These products are marked with a sequence of letters and numbers.
In addition, on one of the sides of the surface there is the mass and production date of the support.
Since the rack is load-bearing, during production a maximum width of shrinkage cracks of no more than 0.2 mm is allowed. At the same time, the length of the column should not be changed by ±60-80 mm, the cross-section – ±6 mm.
According to the requirements of technical documentation, supports may have a deviation in plane<30 мм, а толщина бетона до арматуры не может быть <5 мм от проектной величины.
