Mountain glaciation - This model is
related to many case histories and itself merges into the continental glaciation
and periglacial models and potentially into the temperate model, so that there
is a lot of overlap in this area. This particular model is illustrated by:
Case History 13: Lötschberg Tunnel, Switzerland
Case History 14: Barrage des Échelles d'Annibal, France
Case History 15: Tsho Rolpa proglacial lake, Nepal
Continental glaciation - Again,
this is a potential, common model which we illustrate with:
Case History 16: Pärve Fault, Sweden
Case History 17: Silent Valley, Northern Ireland
Case History 18: Wabamum Lake, Canada
This model merges into mountain glaciation, periglacial and temperate models.
Periglacial - This model is for
areas outside the limits of glaciation and may also be superimposed on former
glacial areas as glaciation retreats. The model is important because it
describes both fossil (i.e. ancient) conditions and currently active conditions.
Case History 19: Sevenoaks By-pass, England
Case History 20: Carsington Dam, England
Case History 21: Empingham Valley, England
Temperate climate - This is an important
model in that it links the various landscapes between cold conditions and the
hot conditions, so it is the model that links Figures 3.18, 3.19 and 3.20 with
Figures 3.22, 3.23 and 3.24. It may well contain relict periglacial or glacial
conditions or even relict hot dry or hot wet conditions as the climate belts
have moved in the Quaternary and a little earlier.
Case History 22: Hadleigh abandoned cliff, England
Case History 23: Vaiont Reservoir, Italy
Hot dry climate - This model is based on hot dry conditions,
i.e. hot deserts, but in some cold deserts similar
conditions also pertain, the unifying feature being lack of rain and, especially
in hot deserts, evaporation exceeding precipitation at all times. This model
merges into the temperate and, depending on the location, may also merge into
the soluble and various coastal models. It is illustrated by Case History 24
which is an example of an ancient hot dry situation. This is another case where
the authors had first hand experience of the successful use of the initial
model. It is also illustrated by Case History 25, a modern desert situation.
Case History 24: Abbey Sewer, Leicester, England
Case History 25: Foundation failures associated with dissolution of a salt dome at Jazan, S.W. Saudi Arabia.
Hot wet climates - Again, like hot dry, there are potentially many case histories relating to modern conditions of this model as well as the occasional ancient conditions. Surprisingly, we have found no case history that we could use as a leading case.
Coastal - This is a particularly
important model because it represents most coasts of the world, all being
subject to the worldwide sea level changes in the Quaternary, which have made
most coasts quite geomorphologically active zones. The coasts themselves would
have been further modified by their hinterland - hot wet, hot dry, periglacial,
and so on. This model produced many case histories of which three have been
selected: Case Histories 22 (already described), 26 and 27. The latter case is
again one in which the authors have had first hand experience. By use of the
models, all the geotechnical conditions contributing to the during-construction
instability were anticipated.
Case History 26: Folkestone Warren, England
Case History 27: Coast of Indonesia
Soluble rock - This model can occur
more or less anywhere in the world and is related to those rocks that dissolve
in relatively short periods of geological time, particularly limestones: gypsum
and other less common evaporite rock types also suffer from similar solubility
characteristics to the limestones, but usually dissolve more quickly. This model
is illustrated by Case Histories 28, 29, 30 and 31.
Case History 28: Penstock at Saint-Jean-de-Maurienne, France
Case History 29: Sinkholes, Far West Rand, South Africa
Case History 30: Wards Island Sewer Tunnel, New York, USA
Case History 31: Kentucky Dam, USA.