Foundation, Concrete and Earthquake Engineering

Corrosion Problem of Steel Piles

According to National Bureau of Standards ( NBS), pile driven in disturbed, or fill, soils will tend to undergo relatively more corrosion. This study is applicable for both sheet-pile and bearing pile. Undistured soils were found to be Oxygen-deficient from a few feet below the ground surface while the disturbed soil contain a high concentration.

The soil considered as corrosion  susceptible, according to NBS, is:

PH   = 2.3 - 8.6  
b)  Electrical resistivity of 300  to 50200 ohm. cm.

Soil exposed to sea water or effluents with a PH much above 9.5 or below 4.0 will required painting or encasement in concrete to resist corrosion. This is also true for zones where the piles are subjected to water fluctuations foe several feet. A splice, increasing section slightly in the corrosive zone, may suitable alternative to the treatment stated above.

Some of the newer grades of high-strength and copper-alloy steels claim substantial corrosion resistance. The A690 high-strength low-alloy steel has approximately two to three times more corrosion resistance to sea water them ordinary carbon steel of A36 grade.

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