Sea water or
Effluents: Piles
exposed to seawater or to effluents with a pH much above 9.5 or below 4.0 will
require painting (i.e., paint the pile, then construct the backfill) or
encasement in concrete to resist corrosion. As an alternative to painting or
concrete encasement, a splice that uses a slightly larger section in the corrosive
zone may be made.
water line fluctuation Zone: In general for
the several feet of zone of water line fluctuation along the pile the corrosion
is also prominent requiring same treatment of painting or concrete encasement.
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Erosion of Steel pipe pile |
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Saline and the erosion of port structures |
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Concrete Pile Jackets |
Disturbed or
filled soils: Piles driven in disturbed, or fill, soils will tend to undergo relatively more
corrosion attributed to a higher oxygen concentration in the disturbed soil and may
require painting or similar other treatment as above. Undisturbed soils were found to be
oxygen-deficient from a few feet below the ground surface.
According to NBS
studies on substructures like both sheet-pile and bearing-pile over 40 years if piles are driven in undisturbed natural soil
deposits, pile corrosion is not great enough to affect the strength of the
piles significantly. These studies covered soils with pH (a pH less than 7 is acidic)
values from 2.3 to 8.6, and electric resistivities of 300 to 50 200 ohm • cm which
was further concluded that as long as the soil was undisturbed, the soil
characteristics and properties are not significant. For a given site soil ohm-cm
(soil resistance) can be used to determine the probability of pile corrosion.
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