Geology Reference
In-Depth Information
avoided. The big problem is identifying whether any particular site
is unforgiving and in what way. It is the task of the engineering geologist,
through his knowledge of geological processes, to anticipate hazardous
geological conditions and to make sure that a GI is properly focused. A
checklist approach to hazard prediction is advocated below.
1. Hazards and constraints during
construction and in the longer term
-
Previous site use
-
obstructions, contamination
-
Any history of mining or other underlying or adjacent
projects (e.g. tunnels or pipelines)
-
Sensitive receivers
such as neighbours that might be
affected by noise, dust, vibration and changes inwater levels
-
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Regulatory restrictions
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Natural hazards, including
flooding, wind, earthquakes,
subsidence and landslides
2. Assess and record site
characteristics
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Access constraints for investigation and
construction
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Need for traf
c control, access for plant and waste
disposal
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Access to services
-
Site condition survey (partly as a record for any future
dispute)
3. Geological pro
le at site
-
Distribution and nature of soil and rock underlying
the site, to an adequate degree, to allow safe and
cost-effective design
-
Usually this will require a sub-surface ground
investigation
4.
Physical properties of soil
and rock units and design
parameters
Key parameters:
-
mass strength (to avoid failure)
-
deformability (to ensure movements are tolerable)
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permeability (
(flow to and from site, response to rainfall and
loading/unloading)
Other factors:
-
chemical stability (e.g. reactivity in concrete, potential
for dissolution)
-
potential for piping and collapse
-
abrasivity (sometimes a major consideration for
construction)
-
-
5. Changes with time
install instruments to check physical nature of the site
e.g.
groundwater response to rainfall
-
install instruments to monitor settlement and effect on
adjacent structures during construction
-
consider the potential for deterioration and need for
maintenance
