Fabrication and Erection of Structural steel building
The process of steel fabrication involves grinding, welding, cutting, bending, drilling, punching, burning or melting and other general crafting methods using various high-quality tools and CNC equipment. The entire steel fabrication process is systematic and requires utmost planning, precision, and knowledge. Steel fabricators are well aware of all the crucial steps and measures that need to be taken care of in the fabrication process. Structural steel is usually fabricated to create structures like beams, trusses, hollow sections, angles and plates.
These steel members must be accurately fabricated before assembling them together. All component parts of these members are fitted-up temporarily with rivets, bolts, or small amounts of welds. Various fastening methods are employed to deliver different types of finishes. Finishing is generally performed by milling, sawing or other suitable methods.
There are four primary tasks that need to be considered before the steel erection process.
– It is extremely important to establish the foundations and confirm if they are suitable and safe for erection to commence.
– With the help of cranes or sometimes by jacking, lifting and placing components into position is essential. Additionally, to secure the components in place, bolted connections are made but they may not be fully tightened. Similarly, bracings may not be fully secured.
– Aligning the structure is essential, principally by checking that column bases are lined and leveled and columns are plumb. To allow column plumb to be adjusted, packing in beam-to-column connections may need to be changed.
– Last but the least, bolting-up is required, which means completing all the bolted connections to secure and impart rigidity.
Steel fabrication and erecting steel structures are a lengthy process and they require immense skills, knowledge, and practice. Our steel fabricators at Northern Weldarc use the best steel fabrication tools and equipment to ensure that the fabrication and erection processes of steel structures are done with accuracy and perfection.
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.
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 (usually defined in our Standards) before final bolting up is completed. The completed steel frame may then be handed over for further work on internal floors, external cladding and mechanical and electrical fitments.
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.
Four design factors to consider in relation to buildability are:
- repetition and standardisation: repetition of the same structural components and common/standard details for connections
- achievable tolerances: if ‘tight’ tolerances are specified (i.e. more restrictive than Class 1 in AS/NZS 5131) then special controls will be needed and possibly specially engineered details
- frame type: the primary choice is between braced frames and continuous frames
- floor systems: for multi-storey frames, the choice of floor system will affect the erection sequence as it determines the stability of the part-erected structure.
What is steel erection work? Steel erection work includes constructing, altering, repairing, maintaining, demolishing and dismantling a steel structure. Steel erection work includes erecting metal structures by joining together steel beams, columns and surfaces to create a metal skeleton. Further information is in the Cranes guidance material.
When does steel erection become high risk construction work? Steel erection work can be high risk construction work when it involves any of the following,
Further information on SWMS is in the Code of Practice: Construction work and the Information Sheet: SWMS for high risk construction work. Steel erection work requires specialised skills and qualifications such as dogging, rigging and crane operation. Workers must be trained and competent including holding the appropriate high risk work licence and instructed in the use of control measures to manage the hazards and risks of steel erection work. Further information is in the Information Sheet:
What do I need to do?
The work health and safety laws require that workers be consulted and given the necessary information, training, instruction and supervision to minimise the risks of steel erection work. A focus on planning and completing detailed designs will help to ensure safety for workers at each stage of the steel erection process.
Design and planning Time spent at the design stage will minimise work involving potentially dangerous onsite remedial work. It can also help to prevent structural instability including progressive collapse and other hazards during erection. There are two distinct phases of design— structural design and the design for handling, transportation and erection of the individual members and the structure.