Steel pile corrosion compensation 1

[DwayneM]

I am assigned to evaluate a design where steel piles (HP section) are being used to support a concrete structure on a recently constructed embankment. The clayey soils are going to settle, possibly a few feet over the design life. The designer has elected to not paint or coat the upper portions of the piles, but instead use an increased thickness (HP14x89 from HP14x73)to allow for corrosion.
Question: Given the conditions of the steel being exposed between the concrete slab and the settled soil surface, is the .101" additional thickness sufficient? I'm concerned that it will be a miosture and air rich environment with no real ability to inspect, let alone repair, corrosion damage.
Material I've found mostly discusses submerged structures, and recommend .125 to .25. I almost want to evaluate this as freshwater splash zone, but don't want to overkill on the conservative side.
[Since the 89's are being used for corrosion comensation, I'm checking the structural design using 73's].

References to accepted design / practice manuals would be appreciated. Thanks!

PS- direct contact with the designer for a "how'd you come up with this?" session is not really feasible.

 

[SlideRuleEra]

I have a document on my website that addresses your question directly. It is "National Bureau of Standards Monograph 58, Corrosion of Steel Pilings in Soils". I agree that the area of the piling that you are concerned about is most subject to corrosion. See this page:

http://www.slideruleera.net/Steel-Piling.html

Also see pages 91 & 92 of the book "Piling Engineering". Those pages are included in the preview here:

http://books.google.com/books?id=_U...esnum=2&ved=0CBkQ6AEwATgK#v=onepage&q&f=false

http://www.SlideRuleEra.net

http://www.VacuumTubeEra.net