Design footing WITH moment
Design footing WITH moment
(OP)
In my undergrad textbook for designing footings, it appears to only deal with column footings that have no moment. So then how would a person design a footing that has vertical and horizontal loads or moments, like a footing with a pipe supported on the pier...which would have wind and seismic horizontal loads? (In terms of all the design, especially pier reinforcing)






RE: Design footing WITH moment
RE: Design footing WITH moment
RE: Design footing WITH moment
RE: Design footing WITH moment
RE: Design footing WITH moment
RE: Design footing WITH moment
Yes, you have to design the pier and the footing for the moment at the base. Your pier will likely have to be at least twice the dimensions of the base plate to get ACI Appendix D to work for your anchor rods.
Be generous with the footing size to keep the eccentric load within the kern (e < L/6) if you can. This will keep the entire footing with at least some bearing on soil. "If you keep the load in the kern, the footing will not overturn"
RE: Design footing WITH moment
Yeah, that's about it. Often these kinds of piers are governed by minimum reinforcing limits. It's common to see 0.5% vertical steel and ties to suit column code rules. Of course, if you loads require more, then you'll have more.
At the top of the pier, you'll have an anchorage connection to design as steellion has mentioned. At the bottom of the pier, you may require two features not common to systems carrying purely axial loads:
1) You may need top steel in your footing and;
2) You may need to turn your starter dowel hooks inwards which is cumbersome.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.