BS 5975-1:2024 - Book - Page 56
BS 5975‑1:2024
BRITISH STANDARD
Table 2 — Categories of design check in temporary works
Category
Scope
Comment
0
Restricted to standard solutions only, to This applies to the use of standard
avoid the site conditions conflicting with solutions and not the original design,
which requires both structural
the scope or limitations of the chosen
calculation and checking to
standard solution. These may include
Category 1, 2 or 3, as appropriate.
standard trench boxes.
Independence of checker
1
For simple designs, such as formwork,
falsework, and needling and propping to
brickwork openings in single‑storey
construction.
Such designs are undertaken using
simple methods of analysis in
accordance with the relevant
standards, supplier’s technical
literature or other reference
publications.
The check may be carried out by
another member of the design
team.
2
For more complex or involved designs,
such as designs for excavations,
including basements excavation support
using sheet piles, for foundations, for
structural steelwork connections and for
reinforced concrete; and designs where
stability is provided by restraint at the
top of the temporary works
(e.g. top‑restrained falsework).
Category 2 checks include designs
where a considerable degree of
interpretation of loading or soils’
information is required before the
design of the foundation or
excavation support or slope is carried
out.
The check should be carried out
by an individual not involved in
the design and not consulted by
the designer.
3
For complex or innovative designs,
which result in complex sequences of
moving and/or construction of either
the temporary works or permanent
works. It also includes deep basement
excavations and tunnels.
These designs include unusual
designs or where significant
departures from standards, novel
methods of analysis or considerable
exercise of engineering judgment are
involved.
The check should be carried out
by another organization and
include an overall check to assure
coordination of the whole design.
Because this is a site issue, the
check may be carried out by
another member of the site or
design team.
NOTE The contents of this table can be developed by each organization's procedures to suit their particular range and scope of
work. The examples given for scope are indicative.
12.7.4
Where different organizations, or individuals, have prepared different parts of a design, the category
of design check should be appropriate to the part of the design being checked.
NOTE 1 For example, if a proprietary supplier is carrying out a falsework design for their equipment, and stability
is assumed by being fixed at the head to the permanent work (i.e. top restrained), the check on the falsework might
be Category 1 but the check that the structure is able to resist the applied horizontal load might be Category 2.
NOTE 2 See also 7.4.2 for the role of the lead designer.
12.7.5
On completion of the design and the design check, certificates should be issued for Category 2 and
Category 3 checks and, where the organization’s procedures require, for Category 1 checks. The
certificates should confirm that the design conforms to the requirements of the design brief, state
the standards/technical literature used and list the constraints or loading conditions imposed. The
certificates should state the category of check and identify the drawings/sketches, specification and
any methodology that are part of the design, and be signed by the designer and design checker. The
package of information issued to the TWC should include these certificates. The design and check
certificate may be presented as separate design and check certificates.
NOTE 1 Neither the designer's nor the design checker's calculations form part of the design compliance items
listed on the signed design certificate.
NOTE 2 Where a standard solution (Category 0) is used, a certificate is issued when the solution is originally
developed (see 12.7.1).
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