Different types of structural steel framing systems for buildings such as skeleton, wall bearing and long span framing systems and their applications and configurations are discussed.
Fig.1: Structural Steel Frame System
Fig.2: Structural Steel Frame
Types of Structural Steel Framing Systems for Buildings
Different types of structural steel framing systems are as follow:
- Skeleton steel framing
- Wall bearing steel framing
- Long span steel framing
Skeleton Steel Framing System
Skeleton steel frame is composed of steel beams and columns which are connected using proper connection. Steel beams around perimeter of the structure is termed as spandrel beams on which masonry walls are placed.
Typical plane views of skeleton framing are shown in Figure-3 and constructed skeleton steel frame are shown in Figure-4. Steel columns, primary and secondary steel beams are shown in the figures.
Fig.3: Plan View of Skeleton Framing
Fig.4: Skeleton Steel Framing
There are different types and configurations of steel connections which are used to connect steel beams to columns in skeleton frame structure, for example, bolt connection and welded connections.
Figure-5 illustrate various types of bolted connection including flexible end plate, fin plate and double angle cleat.
Fig.5: Different Bolt Connection Arrangement used to Connect Beams to Columns
It should be known that all gravity loads in skeleton frame structure are supported by beams and columns. The distance between columns can be established according to the functions and requirements of the structure.
Therefore, there are no restrictions that limit the area of the floor and roof of the building. Multi storey structures are possible to construct using skeleton framing.
Wall Bearing Steel Framing System
In a wall bearing steel framing structure, building wall whether it is interior or exterior is used to carry the end of structural members that support floor or roof loads.
Wall bearing should be adequately strong to not only be able to carry vertical reactions but also to resist any imposed horizontal loads.
Wall bearing framing is suitable for the construction of low rise structure. This is because the size of the bearing wall must be increased significantly to withstand considerably loads exerted in the case of multistory buildings.
This problem might be solved to certain extent if the reinforced concrete walls are applied.
There are several cases in which wall bearing frame system is suitable to be used. For example, single story house in which steel beams are used to carry wall and floor loads and the end of the steel beams are placed on foundation walls, as shown in Figure-6.
A further application of wall bearing system application is the utilization of steel beams known as lintels over wall openings like doors and windows.
Fig.6: The end of steel beam, which support floor loads, is installed on walls, intermediary support (cylindrical steel column) applied to support the beam because the span is large
Fig.7: Using Steel Beam to Support Masonry Lintels
Fig.8: Using Steel Beam to Support Masonry Lintels
Long Span Steel Framing
Long span steel framing is considered when large clearance is required and such long spanning cannot be realized using steel beams and columns.
Long span steel framing options can be categorized into different types, for instance, girders, trusses, rigid frames, arches and cantilever suspension spans.
These classes of long span steel framing options along with their applications and various configurations are provided in Table-1.
Table-1: Long span steel framing types, their applications and various configurations
|Long span framing system types||Application condition||Various types or configuration of the given long span framing system class|
|Girders||It is selected for the case where depth of the member is restricted over a large unobstructed area in lower storeys. The girder should support loads from above storeys across cleared area.||Roller beams, Riveted girder, welded girder, heavy girder, hybrid girder, and a girder consist of two girder fastened|
|Truss, Figure 10||It can be used for the case where restriction on the element depth is not imposed. it an economical way of spanning long distances provided that depth limitation is not existed. Trusses are better compare with other option in controlling deflections due to better stiffness.||Pratt, warren, fink, scissor, bow string and Virendeel|
|Arches, Figure 11||It is used to carry walls and roof with open or solid web arches||Hinge less arches, two hinged arches and three hinged arches|
|Rigid frames, Figure 12||It is used to span long distances. it is aesthetically pleasing that is why applied in the construction of churches, gymnasiums, auditoriums, bowling alleys and shopping centers||Single span rigid frame, welded rigid frame.|
Fig.10: Different types of trusses used in steel structure construction
Fig.11: Types of Arches Used for Steel Structure Construction
Fig.12: Single Span Rigid Frame