Geology Reference
In-Depth Information
UK. Unfortunately, con
icting use of terms was already a feature,
especially regarding rock strength, as illustrated later. Other bodies
(ISRM and IAEG in particular) were meantime setting up their own
working groups and coming up with sets of terms to describe rock
features that were in con
ict with those suggested by others. The ISRM
publication on Suggested Methods for the Quantitative Description of
Discontinuities (ISRM, 1978) is a particularly well-illustrated and
useful guide, but some of the terminology is its own.
This was followed in the UK by the preparation of fuller guidance on
the description and classi
cation of both soil and rock in the BS 5930:
1981 Code of Practice for Site Investigations. Following its publica-
tion, a conference was held to review the BS and papers and discussion
were published as Geological Society Engineering Geology Special
Publication No. 2 (Hawkins, 1986). The Geotechnical Control
Of
ce (1988) published Geoguide 3 on Soil and Rock Descriptions,
which largely followed British practice but with some distinct differ-
ences, especially regarding the description and classi
cation of weath-
ered rock, which is of particular importance to Hong Kong.
BS 5930 was revised and republished in 1999 and is a better docu-
ment. Most recently, amendments have been made as part of the
introduction of the Eurocode, and some of the changes are not neces-
sarily improvements, as discussed by Hencher (2008). Meanwhile,
other countries have adopted their own schemes (e.g. Australia, New
Zealand and China) and whilst there are common aspects, often the
same terms (and certainly the same properties) are rede
ned in differ-
ent ways, which is confusing to say the least. In China, there are
currently separate standards for site investigation for different indus-
tries: transportation, railway, houses and buildings, oil and gas,
mining, hydro-electricity, geological survey and for exploration. US
practice is illustrated by Hunt (2005) and CALTRANS (2010).
Systematic description is generally applicable to ground investigation
-
logging boreholes and exposures. Descriptions should be thorough
and unambiguous so that the end user, perhaps in a design of
ce,
will know what has been observed on site. The scope and style of
routine description of soil and rock for engineering purposes in logging
are well established. Examples are presented in Appendix D and serve
to illustrate the differences in practice internationally.
No preferred order is given in EN ISO 14688 (BSI, 2002) or 14689 (BSI,
2003) so, for the UK, the BS 5939 recommendations should be adopted
in logging. This is largely to encourage the logger to consider all aspects.
