Metal Structures

Development of metallurgy causes increase in production capacity and range of metal building structures.
Rolled steel is used to construct girders of industrial and civil buildings and bridges, manufacture concrete reinforcement, roof steel, pipes, as well as various metal articles, rivets, bolts, nails, screws.
Metal structures are widely used in construction due to their valuable technical properties: high strength, plasticity, increased heat conductivity, electrical conductivity and weldability. However, metals, especially steel and iron, are highly corrodible and require special protection against impact of various gases and moisture.

Metal structures are used in different engineering installations. The following types of engineering installations can be distinguished depending on their structural form and purpose.
1. Single-storey production buildings. Such buildings can include one or multiply spans, as well as spans of various height, integrated working platforms and multi-storey inserts.
2. Low-rise buildings. Former buildings were constructed using bricks, reinforced concrete, wood and other ordinary construction materials. Nowadays, such buildings also include metal structures.
3. High-rise buildings. High-rise buildings are mainly used in civil construction at compact planning of big cities. The design of these buildings definitely divides all structures into bearing and enclosing structures. Metal structures refer to bearing structures, and light wall panels are used as enclosures.
4. Large-span buildings. Large spans are provided in sports facilities, roofed markets, exhibition halls and some types of production buildings (sheds, aircraft assembly shops, etc.). These spans are usually made of metal structures. There are various systems and structural forms of large-span roofs: beam, frame, arc, dome-shaped, suspended and combined roofs, both flat and spatial.
Large-span buildings are mainly loaded by their own weight which can be reduced by utilizing light-weighted enclosing metal structures made of steel of improved and high strength, or by applying various methods of force regulation.
5. Bridges, racks. Some bridges and racks are completely made of metal structures.
There are various systems of bridges and racks: beam, arc, suspended. Beam systems often utilize steal-concrete composite beams. In this case main steel span beams are combined with a driveway concrete plate to ensure their joint bending resistance.
6. Towers and masts. This group of structures includes: antenna assemblies, overhead electric line supports, stacks, towers of off-shore stationary oil and gas platforms.
Tower structures also include geodesic towers, industrial stands, shaft frames, drilling rigs etc.
7. Sheet metal structures are thin-walled plates and shells of various shape.
8. Other types of structures, including steel structures of bridge, tower and gantry cranes, reloading cranes, conveyor bridges, large-size excavators, construction and road machines, gates and shuttles of waterworks, radio telescopes, space-radio antennas etc.
The main advantages of metal structures vs structures of other materials are reliability, light weight, impenetrability, manufacturability, simple reequipping, repair and reconstruction.
The disadvantages of steel structures are corrodibility and relative low fire resistance.
Metal structures shall be designed taking into account the following basic requirements: operation conditions, metal saving, transportability, manufacturability and express installation.
Metal structure longevity depends on its physical and functional depreciation terms. Physical depreciation is mainly caused by corrosion, and functional depreciation - by varied operation conditions.
Type designs of metal structures are widely used in Russia. Typical design solutions of oft-recurring structural components are developed for columns, gantry beam frames, window and lamp crossworks. These typical solutions provides for unified dimensions of components and junctions. Special standards are developed for certain components.
Express installation means metal structures assembly in large units on ground followed by their lifting in design position with minimum installation work on the top. Typical design allows minimizing installation terms and labor intensity because recurring types and structures and their junctions improve utilization of installation equipment and installation process proper.