BS 5975-1:2024 - Book - Page 63
BRITISH STANDARD
BS 5975‑1:2024
6)
whether ground anchors are preferred to internal propping and any restrictions on ground
anchors;
7)
preferred installation and removal sequences and available plant to carry out the work;
8)
equipment available for installing and extracting any sheet piles;
9)
preferred method for controlling water ingress (if required), internal sump pumping, well
pointing, deep wells, etc.;
10) whether any nearby existing buried services need support or protection;
11) if trench/excavation is to be carried out in rock, what the preferred methodology is: drill
and blast, ripping, etc.;
12) access and edge protection requirements; and
13) any mitigation measures that the site team propose to control over‑dig, accidental impact,
formation softening, etc.;
c)
d)
ground investigation:
1)
investigation techniques relevant to the work being carried out and the amount of
investigation appropriate to the anticipated risks;
2)
make‑up of ground (descriptions and depths of layers) and properties (any testing required,
in situ or laboratory), location of investigation and surface datum in relation to work to be
carried out; ground investigation to extend past the bottom of any intended sheeting or
other method of retention;
3)
any evidence of groundwater and artesian pressure (including variation with time);
4)
position, size and depth of existing services crossing the line of trench/excavation and likely
to have been installed in a backfilled trench, where locally the ground conditions might vary;
5)
details of any sloping ground near to the trench/excavation;
6)
evidence of mine workings, sink holes or previous ground instability;
7)
tidal and flow information for cofferdams in rivers or sea; and
8)
if trench/excavating is in rock, information on strength, bedding planes and joints;
obstructions and restrictions:
1)
restrictions on position, width or depth available for battering/stepping or support scheme;
2)
hard surfaces or obstructions that might be encountered and are to be avoided or removed;
3)
noise or vibration restrictions;
4)
deflection limitations on wall (or settlement behind the wall);
5)
craneage or machinery limitations (e.g. for lifting, drilling or driving);
6)
restrictions on use of driving aids such as pre‑augering or water.;
7)
any other restriction imposed by neighbours (e.g. Network Rail); and
8)
the need for any guide walls or piling gates to achieve installation tolerances especially if
contractual tolerances are “non‑standard”;
© THE BRITISH STANDARDS INSTITUTION 2024 – ALL RIGHTS RESERVED 55
