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A steel building is a metal structure fabricated with steel for the internal support and for exterior cladding, as opposed to steel framed buildings which generally use other materials for floors, walls, and external envelope. Steel buildings are used for a variety of purposes including storage, work spaces and living accommodation. They are classified into specific types depending on how they are used.
Steel buildings first gained popularity in the early 20th century. Their use became more widespread during World War II and significantly expanded after the war when steel became more available. Steel buildings have been widely accepted, in part due to cost efficiency. The range of application has expanded with improved materials, products and design capabilities with the availability of computer aided design software.[ citation needed ]
Steel provides several advantages over other building materials, such as wood:
Some common types of steel buildings are "straight-walled" and "arch," or Nissen or Quonset hut. [4] Further, the structural type may be classed as clear span or multiple span. A clear span building does not have structural supports (e.g. columns) in the interior occupied space.
Straight-walled and arch type refer to the outside shape of the building. More generally, these are both structural arch forms if they rely on a rigid frame structure. However, curved roof structures are typically associated with the arch term.
Steel arch buildings may be cost efficient for specific applications. They are commonly used in the agricultural industry. Straight-walled buildings provide more usable space when compared to arch buildings. They are also easier to blend into existing architecture. Straight-walled buildings are commonly used for commercial, industrial, and many other occupancy types.
Clear span refers to the internal construction. Clear span steel buildings utilize large overhead support beams, thus reducing the need for internal supporting columns. Clear span steel buildings tend to be less cost efficient than structures with interior columns. However, other practical considerations may influence the selection of framing style such as an occupancy where interior structural obstructions are undesirable (e.g. aircraft hangars or sport arenas). [5]
Long Bay buildings are designed for use in bay spans of over 35'. They use prefabricated metal frames combined with conventional joists to provide larger openings and clearances in buildings.
The Flospan frameless building system is a lightweight steel building system utilized in over 30 countries. It is notable for its ease of assembly, requiring no cranes or specialized equipment. Flospans can be moved and reused without material loss and demonstrate resilience against severe weather conditions.
Uniports, originating in the UK in 1965 after being pioneered by Alfred Booth & Co in 1948, have been widely deployed worldwide, including in Arctic Canada, the African jungle, and the Kuwait desert. They are easily assembled with basic tools, suitable for unskilled labor, and can be swiftly disassembled and relocated. Uniports offer versatility, allowing for extensions and connections, along with insulation and partition options. Compact and efficient, up to 60 Mark 1 Uniports can be packed into a single 20-foot container.
Building portions that are shop assembled prior to shipment to site are commonly referenced as prefabricated. The smaller steel buildings tend to be prefabricated or simple enough to be constructed by anyone. Prefabrication offers the benefits of being less costly than traditional methods and is more environmentally friendly (since no waste is produced on-site). [6] The larger steel buildings require skilled construction workers, such as ironworkers, to ensure proper and safe assembly. [7]
There are five main types of structural components that make up a steel frame - tension members, compression members, bending members, combined force members and their connections. Tension members are usually found as web and chord members in trusses and open web steel joists. Ideally tension members carry tensile forces, or pulling forces, only and its end connections are assumed to be pinned. Pin connections prevent any moment(rotation) or shear forces from being applied to the member. Compression members are also considered as columns, struts, or posts. They are vertical members or web and chord members in trusses and joists that are in compression or being squished. Bending members are also known as beams, girders, joists, spandrels, purlins, lintels, and girts. Each of these members have their own structural application, but typically bending members will carry bending moments and shear forces as primary loads and axial forces and torsion as secondary loads. Combined force members are commonly known as beam-columns and are subjected to bending and axial compression. Connections are what bring the entire building together. They join these members together and must ensure that they function together as one unit. [8]
Structural engineering is a sub-discipline of civil engineering in which structural engineers are trained to design the 'bones and joints' that create the form and shape of human-made structures. Structural engineers also must understand and calculate the stability, strength, rigidity and earthquake-susceptibility of built structures for buildings and nonbuilding structures. The structural designs are integrated with those of other designers such as architects and building services engineer and often supervise the construction of projects by contractors on site. They can also be involved in the design of machinery, medical equipment, and vehicles where structural integrity affects functioning and safety. See glossary of structural engineering.
A truss is an assembly of members such as beams, connected by nodes, that creates a rigid structure.
In architecture and structural engineering, a space frame or space structure is a rigid, lightweight, truss-like structure constructed from interlocking struts in a geometric pattern. Space frames can be used to span large areas with few interior supports. Like the truss, a space frame is strong because of the inherent rigidity of the triangle; flexing loads are transmitted as tension and compression loads along the length of each strut.
A beam is a structural element that primarily resists loads applied laterally across the beam's axis. Its mode of deflection is primarily by bending, as loads produce reaction forces at the beam's support points and internal bending moments, shear, stresses, strains, and deflections. Beams are characterized by their manner of support, profile, equilibrium conditions, length, and material.
A truss bridge is a bridge whose load-bearing superstructure is composed of a truss, a structure of connected elements, usually forming triangular units. The connected elements, typically straight, may be stressed from tension, compression, or sometimes both in response to dynamic loads. There are several types of truss bridges, including some with simple designs that were among the first bridges designed in the 19th and early 20th centuries. A truss bridge is economical to construct primarily because it uses materials efficiently.
Seismic retrofitting is the modification of existing structures to make them more resistant to seismic activity, ground motion, or soil failure due to earthquakes. With better understanding of seismic demand on structures and with recent experiences with large earthquakes near urban centers, the need of seismic retrofitting is well acknowledged. Prior to the introduction of modern seismic codes in the late 1960s for developed countries and late 1970s for many other parts of the world, many structures were designed without adequate detailing and reinforcement for seismic protection. In view of the imminent problem, various research work has been carried out. State-of-the-art technical guidelines for seismic assessment, retrofit and rehabilitation have been published around the world – such as the ASCE-SEI 41 and the New Zealand Society for Earthquake Engineering (NZSEE)'s guidelines. These codes must be regularly updated; the 1994 Northridge earthquake brought to light the brittleness of welded steel frames, for example.
In structural engineering, a shear wall is a two-dimensional vertical element of a system that is designed to resist in-plane lateral forces, typically wind and seismic loads.
An I-beam is any of various structural members with an I or H-shaped cross-section. Technical terms for similar items include H-beam, w-beam, universal beam (UB), rolled steel joist (RSJ), or double-T. I-beams are typically made of structural steel and serve a wide variety of construction uses.
A tie, strap, tie rod, eyebar, guy-wire, suspension cables, or wire ropes, are examples of linear structural components designed to resist tension. It is the opposite of a strut or column, which is designed to resist compression. Ties may be made of any tension resisting material.
Steel frame is a building technique with a "skeleton frame" of vertical steel columns and horizontal I-beams, constructed in a rectangular grid to support the floors, roof and walls of a building which are all attached to the frame. The development of this technique made the construction of the skyscraper possible.
Formwork is molds into which concrete or similar materials are either precast or cast-in-place. In the context of concrete construction, the falsework supports the shuttering molds. In specialty applications formwork may be permanently incorporated into the final structure, adding insulation or helping reinforce the finished structure.
A girder is a beam used in construction. It is the main horizontal support of a structure which supports smaller beams. Girders often have an I-beam cross section composed of two load-bearing flanges separated by a stabilizing web, but may also have a box shape, Z shape, or other forms. Girders are commonly used to build bridges.
Portal frame is a construction technique where vertical supports are connected to horizontal beams or trusses via fixed joints with designed-in moment-resisting capacity. The result is wide spans and open floors.
In mechanical engineering, stressed skin is a rigid construction in which the skin or covering takes a portion of the structural load, intermediate between monocoque, in which the skin assumes all or most of the load, and a rigid frame, which has a non-loaded covering. Typically, the main frame has a rectangular structure and is triangulated by the covering; a stressed skin structure has localized compression-taking elements and distributed tension-taking elements (skin).
A wall stud is a vertical repetitive framing member in a building's wall of smaller cross section than a post. It is a fundamental element in frame building.
In structural engineering, the open web steel joist (OWSJ) is a lightweight steel truss consisting, in the standard form, of parallel chords and a triangulated web system, proportioned to span between bearing points.
Cold-formed steel (CFS) is the common term for steel products shaped by cold-working processes carried out near room temperature, such as rolling, pressing, stamping, bending, etc. Stock bars and sheets of cold-rolled steel (CRS) are commonly used in all areas of manufacturing. The terms are opposed to hot-formed steel and hot-rolled steel.
In structural engineering, a pre-engineered building (PEB) is designed by a PEB supplier or PEB manufacturer with a single design to be fabricated using various materials and methods to satisfy a wide range of structural and aesthetic design requirements. This is contrasted with a building built to a design that was created specifically for that building. Within some geographic industry sectors pre-engineered buildings are also called pre-engineered metal buildings (PEMB) or, as is becoming increasingly common due to the reduced amount of pre-engineering involved in custom computer-aided designs, simply engineered metal buildings (EMB).
A Rigid-frame bridge is a bridge in which the superstructure and substructure are rigidly connected to act as a continuous unit. Typically, the structure is cast monolithically, making the structure continuous from deck to foundation. The connections between members are rigid connections which transfer bending moment, axial forces, and shear forces. A bridge design consisting of a rigid frame can provide significant structural benefits, but can also be difficult to design and/or construct.
This glossary of structural engineering terms pertains specifically to structural engineering and its sub-disciplines. Please see glossary of engineering for a broad overview of the major concepts of engineering.
