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Steel Designers' Manual - 6th Edition (2003)
1006 Erection
Proper consideration of all of the above issues at the drawing-board stage will
preclude resort to risk-laden, hastily improvised on-site solutions by unqualified
personnel.
33.9.4 Employees’ first visit to site
A tour of the site should be made during the induction process to aid in the identification
and location of key personnel and citing of equipment, fire and first aid
points, etc. Procedures should be laid down and constantly reviewed for any
employee joining a company.
33.9.5 The safety of the structure
The safety of those working on a structure is prescribed by statutory regulations.
However, the stability of the structure itself is not prescribed by any regulation.
Where a collapse of a partly built structure occurs, the loss of life is generally heavy.
Post-collapse investigation and inquest often show gaps in the understanding of the
behaviour of the incomplete structure; lapses in the detailed consideration of each
and every temporary condition; and, most important of all, blocks in the flow of
communication of information to all involved. In the bridge collapse shown in Fig.
33.21 the temporary loading condition was not considered properly. At the point of
failure of the bottom flange, a splice similar to that shown in Fig. 33.22 was unable
to take the compression imposed during erection.
A designer must communicate the plan for building the structure to those who
will actually have to do the building. In order to realize the design, the designer
must be able to successfully translate the planning stage into the construction phase.
Columns
The end restraints of a column can change during the construction of a building;
each condition must be checked to ensure that column capacity is not compromised.
The risks inherent at each stage must be assessed and provided for, taking into
account location, height, loads, temporary conditions, etc.
Plate girders and box girders
The checks which are applied to the webs and stiffeners of a plate girder during its
design normally take account only of conditions at points where stiffeners are
located and at points where loads are applied to the girder. It may not be obvious
to the designer of a bridge girder that it may be subjected to a rolling load when