Geology Reference
In-Depth Information
4
'…
if you do not know what you should be looking for in a site investiga-
tion you are not likely to
find much of value.
'
(Glossop, 1968)
This much-quoted quote is worth repeating because it sums up the
philosophy of site investigation very well. Critical features need to be
anticipated and looked for. Without care, the important details might
be hidden within a pile of essentially irrelevant information. The
dif
culty and skill, of course, is in recognising what is critical.
At any site, the ground conditions need to be assessed to enable safe
and cost-effective design, construction and operation of civil engineer-
ing projects. This will generally include sub-surface ground investiga-
tion (GI), which needs to be focused on the particular project needs and
unknowns. The requirements for GI will be very different for a tunnel
compared to the design of foundations for a high-rise building or for
stability assessment of a cut slope. There needs to be a preliminary
review of the nature of the project, the constraints for construction and
the uncertainties about the engineering geological conditions at the
site. The British Code of Practice for Site Investigation, BS 5930 (BSI,
1999), sets out the objectives broadly as follows:
1. Suitability: to assess the general suitability of a site and its environs
for the proposed works.
2. Design: to enable an adequate and economic design, including for
temporary works.
3. Construction: To plan the best method of construction and, for
some projects, to identify sources of suitable materials such as
concrete aggregate and
fill and to locate sites for disposal of waste.
4. Effect of changes: to consider ground and environmental changes
on the works (e.g. intense rainfall and earthquakes) and to assess the
impact of the works on adjacent properties and on the environment.
5. Choice of site: where appropriate, to identify alternative sites or to
allow optimal planning of the works.
