Individual helical anchors as column supports
Individual helical anchors as column supports
(OP)
Any body have experience with individual helical anchors as bearing support for independent columns?
I've been a little reluctant in the past to consider helical anchors, I guess its the engineer/inertia issue.
I'm working on a small project that has limited space and where a lot of excavation causes problems. The idea is to drill in single helical anchors under each of 10 columns supporting a braced elevated deck and pour a cap on top of the anchor with some sort of void under thae cap to accomodate frost expansion. Maximum column loads are 35K. Multiple anchors per column area nice solution for me but raise the eyebrow of the Arch/Owner.
Thoughts?
I've been a little reluctant in the past to consider helical anchors, I guess its the engineer/inertia issue.
I'm working on a small project that has limited space and where a lot of excavation causes problems. The idea is to drill in single helical anchors under each of 10 columns supporting a braced elevated deck and pour a cap on top of the anchor with some sort of void under thae cap to accomodate frost expansion. Maximum column loads are 35K. Multiple anchors per column area nice solution for me but raise the eyebrow of the Arch/Owner.
Thoughts?






RE: Individual helical anchors as column supports
If you know of a lateral and moment capacity of the anchors, you can probably back calculate a tolerance for the eccentricity on the anchor once it and the column are installed. Otherwise it sounds like you would need multiple anchors, probably at least three to make field tolerance more reasonable.
RE: Individual helical anchors as column supports
Or - if you use one pile, use grade beams in two directions to take out the eccentricity. It probably wouldn't take much grade beam to do the job unless your column load is large...but then you'd probably have multiple piles anyway. I think for most uses, the helical piling carries capacities in the 10,000 lb. to 20,000 lb. range.
RE: Individual helical anchors as column supports
Another possible solution is GEOPIERS.
GEOPIER is a rammed aggregate pier below the footing.
The GEOPIER increases the allowable soil bearing and reduces settlement.
All this of course depends on soil conditions.
Cost may be an issue. I have never compared GEOPIERS to helical anchors.
RE: Individual helical anchors as column supports
RE: Individual helical anchors as column supports
RE: Individual helical anchors as column supports
RE: Individual helical anchors as column supports
Some other things to consider might be mini-piles or auger-cast piles if low overhead is a concern. However, these technologies would most likely be more expensive.
RE: Individual helical anchors as column supports