How to Erect a Steel Building
The erection of structural steelwork consists of the assembly of steel components into a frame on site. The components are then lifted and placed into position before they are connected together.
Steel erection essentially consists of four main tasks:
• Establishing that the foundations are suitable and safe for erection to commence.
• Lifting and placing components into position, generally using cranes but sometimes by jacking. To secure components in place bolted connections will be made, but will not yet be fully tightened. Bracings may similarly not be fully secured.
• Aligning the structure, principally by checking that column bases are lined and level and columns are plumb. Packing in beam-to-column connections may need to be changed to allow column plumb to be adjusted.
• Bolting-up which means completing all the bolted connections to secure and impart rigidity to the frame.
Generally, connection is achieved through bolting but, in some cases, site welding is used. The assembled frame needs to be aligned to within tolerance expectations before final bolting up is completed.
The completed steel frame may then be handed over to following trades in an acceptable condition.
Design for construction
The successful construction (including erection) of steel structures safely, quickly and economically starts long before the actual steelwork arrives on site from the fabrication shop. The ‘buildability’ of the structure is influenced significantly by decisions made during the design process long before erection commences.
It is important that designers clearly understand the impact of their decisions. Design for construction is a valid design objective and one that should be considered along with the other usual design objectives in play.
Planning for erection should start at the very beginning of the design process. Such planning should consider the construction sequence, the design factors that affect buildability and site practice in terms of typical erection plant.
In the broader design and planning context, there are three planning factors that affect the buildability of steel structures:
1. Practical erection sequence: the location of both temporary and permanent bracing systems or other means of maintaining structural equilibrium are crucial here
2. Simplicity of assembly: simply assembled connections are the main factor here
3. Logical trade sequences: which will affect the development of the master contract programme as the pre-tender plan metamorphoses into the construction plan.
Tekmetsan supports its clients during the erection works and offers free consultation and installation guideline to assist the clients.