BS 5975-1:2024 - Book - Page 60
BS 5975‑1:2024
BRITISH STANDARD
13.2.1.2
The PC’s TWC, an authorized TWC or an authorized TWS as identified in the implementation plan,
should verify that a permit to load or proceed (bring into use) is issued to the site team prior to
bringing intouse the temporary works [as recommended in 10.2.3s), 10.3.3x) and 11.3j)].
13.2.1.3
The permit to load (or proceed), issued prior to release of the hold point, should confirm that:
13.2.2
13.2.2.1
a)
the temporary works has been constructed in accordance with the certified design (design and
design check certificates have been issued and the drawings and specification used are those
referenced on the certificates);
b)
any modifications to the temporary works have been approved by the designer; and
c)
the water, ground and environmental conditions and use are as envisaged by the design.
Unloading (taking out of use)
Where the temporary works is used to provide support to the permanent works until it is
self‑supporting, the PC’s TWC, TWC or TWS, as identified in the implementation plan, should
determine that the permanent works have attained adequate strength and/or stability, with reference
to the PWD’s specification or in conjunction with the PWD if necessary, prior to issuing a permit to
unload or proceed (take out of use), as stated in 10.2.3u).
NOTE A TWC or TWS may issue the permit for a defined scope and range of work if authorized to do so by the PC’s
TWC in the implementation plan [see 10.3.3y) and 11.3k)]; for example, they might need to verify concrete strength
or that all structural steelwork elements and connections are completed or that any post-tensioning has been
carried out prior to issuing the permit.
13.2.2.2
The sequence and order of removing temporary works, where critical, should be defined in the design
output and/or confirmed in the implementation plan. The sequence should be referenced in the
permit to unload or permit to proceed.
13.2.2.3
Generally the supports to spanning members should be removed, starting mid‑span, and for cantilever
sections, should be removed starting at the tip. The PC’s TWC, or TWC where appointed, should refer
to the permanent works and/or temporary works designer if in any doubt about the sequence.
NOTE The sequence and order of removing temporary works supports can be critical to avoid damage to the
permanent works under construction.
13.2.2.4
The sequence and level of props removed during back‑propping operations should be agreed by the
PC’s TWC or the TWC with the permanent works designer and be included in the implementation
plan (see also 13.1).
NOTE The sequence and level of props removed during back-propping operations is particularly important to
avoid overloading of the completed slabs.
13.3
Dismantling
When it reaches the end of its use, e.g. the structure being supported has become self‑supporting or
the excavation has been backfilled, the temporary works should be dismantled (removed) in
accordance with any restrictions imposed by the permanent works designer as set out in the
implementation plan. As at the loading stage, a permit to dismantle the temporary works might be
appropriate, particularly where this takes place in stages. Care should be taken to keep the temporary
works stable during all stages of the dismantling process.
52 © THE BRITISH STANDARDS INSTITUTION 2024 – ALL RIGHTS RESERVED
