At the present time, many-sided towers are gaining popularity in many countries, including Russia - they withstand the adverse effects of the environment, are easy to install, transport, durable, do not require complicated maintenance.
Product Features
Multifaceted metal supports are made of low alloy steel. Only special grade steel is used in the production. To connect the individual elements, bolts or welding are used. In order to prevent corrosion and oxidation, all steel elements are subjected to one of the following processes:
- Painting with special paints. This option is the final stage of production. Pros - quick staining. Cons - the need to constantly inspect products and periodically re-paint them.
- Hot dip galvanizing. To do this, the manufactured elements are immersed in containers in which molten zinc is located. Its temperature is about +450 degrees. Due to the protective layer, whose thickness is only about 120 microns, the structures will not corrode for at least 25 years. Pros - it is not necessary to observe and repair zinc-coated structures. Cons - higher cost.
Construction application
Multifaceted supports made of metal are an excellent alternative to products made of other materials - wood (impractical), reinforced concrete (short-lived - the products crack under the influence of the environment, chips appear on them).
What is important for installation - the products are disassembled, making them much easier to deliver to the installation site. This, in turn, reduces transportation costs: it is not necessary to hire special equipment for delivery. Already in place, using bolts or welding, the structures are assembled.
Who makes the supports?
A variety of companies in Kazan, Orenburg, Podolsk, Yekaterinburg and many other cities of Russia carry out the production of metal structures under the power transmission line. Such a large number of enterprises is caused by the demand for this type of product: many power lines need reconstruction, so metal structures are constantly in demand.
The Ural Polyhedral Plant is one of the most famous manufacturers. In order to be able to produce products of the highest quality using hot-dip galvanizing, the latest Italian production lines were installed at the factory. This allows galvanizing structures weighing up to 8 tons.
Since the plant was recently founded, it was originally developed according to the requirements of today. Thanks to the coordinated work of carefully selected personnel applying the best world developments in their work, the Ural ZMO has become one of the best enterprises engaged in the production of metal structures of the highest quality.
Product Types
Currently, for double-circuit and single-circuit power lines, polyhedral supports of various types are manufactured. All of them are easily modifiable by:
- Wall thickness.
- The diameter of the structure.
- Altitude and other parameters.
The support is classified into categories and by purpose, design, number of chains. Products are:
- Anchor-angular. With their help, they equip the lines where they change direction, change the cross section
- End. They are used where it is necessary to compensate for the tension at the end of the segment.
- Transient. Use when the line passes through special facilities or natural obstacles.
- Intermediate. Needed to provide support for cables and wires. Mounted on straight sections of tracks. Not suitable for use in direct areas with heavy loads.
- Transpositional. Used to transform the wire.
- Branching. Set for branch lines.
- Cross. Use structures for installation at the intersection of two lines.
Products vary in design features, according to which products can:
- To be free-standing.
- Have braces.
- Have atypical dimensions.
Design Features
To make multifaceted power transmission line supports, the initial steel sheets on special equipment are bent into a closed profile having a multifaceted section. The transverse indicators of the elements do not have a stable indicator: at the base they are much larger and decrease when moving to the top. Automatic welding fix the profile in a single element.
For each pore, several sections are made, from which they then make up the structure using a telescopic or flange connection.
When fixing the structure using flanges, it is necessary to mount the reinforcement using stiffeners. Due to this, all loads will be distributed along the length of the entire support. The conical shape of the product provides a lower center of mass of the support and at each section - the optimal load. Traverses for bearing wires are made either in the form of gratings, or in the form of insulation.
Benefits
Multifaceted metal supports have many important advantages, which are deprived of analogues from other materials:
- Durability, reliability. Zinc-coated metal can last at least 70 years.
- Cost reduction. Multifaceted support structures have high strength, so they can be installed in large increments. Due to this, the complexity of installation and material consumption are reduced.
- The facilitated transportation. To transport the telescopic sections, they are placed one on the other.
- Adaptability. The use of a single technology and the use of automated design systems is a guarantee of the quick manufacture of structures for specific conditions.
- Shorter installation times. If you compare the installation of multifaceted products with reinforced concrete or wooden analogues, the figures obtained may differ by 4 or more times. So, to connect the sections to a brigade of 7 people it may take about one hour. In addition, it will take about 40 minutes to secure the traverse and the same amount of time to install the product on the base and its subsequent fixation.
- Reduced land acquisition costs. As the distance between the supports increases, fewer structures will need to be installed on the line.
- Relative lightness - structures are not monolithic products, so their weight is much less than the same reinforced concrete counterparts.
- The ability to withstand harsh environmental conditions, including cyclic and dynamic loads, high / low temperatures, various types of precipitation.
- Facilitated repair or reconstruction - products are easy to dismantle and upgrade, reducing / increasing the number of sections.
Convenience of transportation
Conical telescopic bearings have a special design. Thanks to this, loading and unloading and transport operations are significantly reduced: in order to transport the structure to the right place, you do not need special equipment, bearing trucks, platform couplers. Each section has a length of not more than 11.5 m, so they can be transported using ordinary gondola cars or caravans for this purpose. During the movement of loading / unloading, the products retain their integrity and are not damaged.
Installation work
Installation of metal supports is quite simple and convenient. Since one section weighs no more than a ton, and a double-chain support does not exceed 2,200 kg, it is not necessary to use complex and expensive lifting equipment to install them. In addition, to install the multifaceted poles of the overhead lines, you do not need a large space. This indicator is very important when products have to be installed in settlements, especially in cities.
When installing the structure, one of the following methods is used:
- In a drilled foundation pit.
- On the anchor foundation.
- On a tubular foundation. To do this, a pipe of the desired diameter is buried in the ground. Then, a support is mounted on the flanges.
The choice of the most suitable method depends on the type of soil, region and climate.
Important points
Scientists and designers conducted a number of studies and made the following conclusions:
- Products are more profitable to use in areas that are characterized by difficult transportation, construction and severe climatic conditions.
- If you take into account the valuation of construction, conical supports are more profitable. in comparison with reinforced concrete or trellised.
- It is most expedient to apply lighting poles multifaceted in projects where they can be applied as efficiently as possible. Such areas can be considered not only urban conditions, but also mountainous, remote and northern regions.
The topic is quite complicated. However, if you delve into it, everything becomes quite clear.