Geoscience Reference
In-Depth Information
14.8 Economic and environmental risk
Environmental risk can also include political risk, and consequences to the
perception of the project.
Table 14.8 Economic and environmental risk (adapted from GEO, 1984).
Situation
Risk
Open farmland, country parks, lightly used recreation areas of low
Negligible
amenity value
Country roads and low traffic intensity B roads, open air car parks
Negligible
Facilities whose failure would cause only slight pollution
Negligible
Essential services (eg gas, electricity, water, whose failure would cause
Low
loss of service)
Facilities whose failure would cause significant pollution or severe loss
Low
of amenity (cultivated public gardens, with established and mature trees)
High traffic density B roads and all A roads, residential, low rise
Low
commercial, industrial and educational properties
Facilities whose failure would cause significant pollution
High
Essential services whose failure would cause loss of service for a
High
prolonged period
All A Roads, by- passes and motorways, including associated slip roads,
High
petrol stations and service areas
Buildings storing hazardous goods, power stations (all types), nuclear,
High
chemical, and biological complexes
14.9 Cut slopes
The stability is dependent on the height of the slope. Table applies only to low to
medium height slopes.
Benches may be required.
Table 14.9 Typical batters of excavated slopes (Hoerner, 1990).
Material
Slope batters (Vertical : Horizontal)
Permanent
Temporary
Massive rock
1.5V: 1H to Vertical
1.5V: 1H to Vertical
Well jointed/bedded rock
1V: 2H to 2V: 1H
1V: 2H to 2V: 1H
Gravel
1V: 2H to 1V: 1H
1V: 2H to 1V: 1H
Sand
1V: 2.5H to 1V: 1.5H
1V: 2.5H to 1V: 1H
Clay
1V: 6H to 1V: 2H
1V: 2H to 2V: 1H
Water levels often dictate the slope stability.
Table assumes no surcharge at the top.
A guide only. Slope stability analysis required.
 
 
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