Cold - Formed Steel Driven Piles & Potential Corrosion Issues
Cold - Formed Steel Driven Piles & Potential Corrosion Issues
(OP)
I am designing ground mount support system for some solar panels. The client is suggesting to extend the columns of the structure to be used as foundation (basically flagpole, IBC 1807.3.2.1). If we went this route, we are going to use galvanized cold-formed steel members however I want to know if I should account for some level of corrosion decay over a period of 25 years (service life). Does anyone have experience in this?
According to the geotechnical report, no water was found when they drilled 15 ft into the ground which is more than what the future foundation would be. However, given the corrosive nature of soil, and the fact that this is near a water basin, I am thinking shouldn't I take something in consideration since this is not a concrete caisson pile but rather a bare steel member?
Any thoughts or advise would be much appreciated. Thanks you.
According to the geotechnical report, no water was found when they drilled 15 ft into the ground which is more than what the future foundation would be. However, given the corrosive nature of soil, and the fact that this is near a water basin, I am thinking shouldn't I take something in consideration since this is not a concrete caisson pile but rather a bare steel member?
Any thoughts or advise would be much appreciated. Thanks you.






RE: Cold - Formed Steel Driven Piles & Potential Corrosion Issues
Usually, the allowable pile stress (as per code) are low enough to where you are covered for structural steel. However, I typically include a bit of a corrosion allowance anyway. In your case, it sounds like you are using light gauge steel......I would recommend such members for that type of application (even if galvanized) because they are so thin.
RE: Cold - Formed Steel Driven Piles & Potential Corrosion Issues
RE: Cold - Formed Steel Driven Piles & Potential Corrosion Issues
I can't see a cold formed section liking that...
RE: Cold - Formed Steel Driven Piles & Potential Corrosion Issues
TLHS, please elaborate. Thanks.
RE: Cold - Formed Steel Driven Piles & Potential Corrosion Issues
RE: Cold - Formed Steel Driven Piles & Potential Corrosion Issues
RE: Cold - Formed Steel Driven Piles & Potential Corrosion Issues
RE: Cold - Formed Steel Driven Piles & Potential Corrosion Issues
RE: Cold - Formed Steel Driven Piles & Potential Corrosion Issues
WARose, regarding the 1/16", over what period of time? I know that depends on the corrosion properties of the soil for a given location and the type of metal, but can you give me a reference where I can find a conservative estimate or just get a general idea. Thanks.
RE: Cold - Formed Steel Driven Piles & Potential Corrosion Issues
Are planning on driving these piles?
RE: Cold - Formed Steel Driven Piles & Potential Corrosion Issues
I actually looked at a reference I have on this last night (after I read your post). It is: "Corrosion of Steel Pilings in Soils", Monograph 58, National Bureau of Standards, US Department of Commerce (1962).
Basically they pulled a bunch of piling and sheet piling that had been in the ground for between 7 to 40 years (in soil that had a pH range from 2.3 to 8.6). The observed degradation (given in percentages) varied greatly and I don't have an average for it but I'd say most of the time it was around 10%. (With a range of values from virtually none to as high as 30%.) From that, I arrived at the values I've typically used.