Design of Bell & Shaft Drilled Pier Foundation for Pre-Engineered METAL BUILDING
Design of Bell & Shaft Drilled Pier Foundation for Pre-Engineered METAL BUILDING
(OP)
I am working on designing a metal building foundation using bell & shaft drilled piers. The foundation is a slab-on-grade with perimeter grade beams. The net allowable bearing pressure is 3000 psf for dead load plus sustained live load which can be increased 25 percent for total load conditions. The issue that I am having are the reaction forces provided by the metal building fabricator for the columns. For one of the columns I am getting DL(vert.)= 10k, LL(vert.)= 15k, Floor Load(vert.)= 17.2 k, Wind Load (vert.) = -16 k, and Wind Load (horiz.) = 11.0k. Is it normal to have such high horiz. loads for a column? I am new to designing foundations for Pre-Engineered Metal Buildings. For most buildings, I designed the piers to resist the downward gravity loads. Using the reactions provided by the metal Building manufacturer, I am getting that I need a ridiculously large shaft/bell size, like a 34/102. I am interested in any insight in what I may be doing wrong, what I am not considering, or if I am allowed to just mostly rely on the gravity loads for my design. Any suggestions/comments are appreciated.






RE: Design of Bell & Shaft Drilled Pier Foundation for Pre-Engineered METAL BUILDING
RE: Design of Bell & Shaft Drilled Pier Foundation for Pre-Engineered METAL BUILDING
2. 3000 psf is very low for end bearing on a drilled shaft. Are you sure that's correct.
RE: Design of Bell & Shaft Drilled Pier Foundation for Pre-Engineered METAL BUILDING
RE: Design of Bell & Shaft Drilled Pier Foundation for Pre-Engineered METAL BUILDING
BA
RE: Design of Bell & Shaft Drilled Pier Foundation for Pre-Engineered METAL BUILDING
RE: Design of Bell & Shaft Drilled Pier Foundation for Pre-Engineered METAL BUILDING
RE: Design of Bell & Shaft Drilled Pier Foundation for Pre-Engineered METAL BUILDING
RE: Design of Bell & Shaft Drilled Pier Foundation for Pre-Engineered METAL BUILDING
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.
RE: Design of Bell & Shaft Drilled Pier Foundation for Pre-Engineered METAL BUILDING
@KootK - My goal is to have the piers resist the horiz. forces. Next I was going to try and convert the horiz. forces into couple moments. Or just determine the moment caused by the horizontal force to my pier and determine the max moment the pier can handle.
@everyone/anyone - Would the slab-on-grade system (i.e. grade beams, 6" th'k slab) already take care of the horiz. forces? Also, I have read online something about using hairpins to handled the horizontal loads.
RE: Design of Bell & Shaft Drilled Pier Foundation for Pre-Engineered METAL BUILDING
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.
RE: Design of Bell & Shaft Drilled Pier Foundation for Pre-Engineered METAL BUILDING
RE: Design of Bell & Shaft Drilled Pier Foundation for Pre-Engineered METAL BUILDING
BA
RE: Design of Bell & Shaft Drilled Pier Foundation for Pre-Engineered METAL BUILDING
@BAretired - Would hairpins be expensive to use?
RE: Design of Bell & Shaft Drilled Pier Foundation for Pre-Engineered METAL BUILDING
BA
RE: Design of Bell & Shaft Drilled Pier Foundation for Pre-Engineered METAL BUILDING
If there are no rigid frames, I suspect that the lateral loads for wind are from rod bracing system. These I would feel comfortable taking into the piers and resisting by passive soil pressures.
If you are in an area of expansive soils, be careful how the slab/ footing interface is handled.
RE: Design of Bell & Shaft Drilled Pier Foundation for Pre-Engineered METAL BUILDING
@everyone - Is it typically common to have hairpins in a metal building foundation?
RE: Design of Bell & Shaft Drilled Pier Foundation for Pre-Engineered METAL BUILDING
BA
RE: Design of Bell & Shaft Drilled Pier Foundation for Pre-Engineered METAL BUILDING
Jimstructures
RE: Design of Bell & Shaft Drilled Pier Foundation for Pre-Engineered METAL BUILDING
I have the PIP STE05121 Anchor Bolt Design Guide. I have never designed/used hairpins before but I am hoping it is the same as what is mentioned in PIP. Would any body familiar with hairpins be able to let me know what direction I should go in designing and installing hairpins for a PEMB?
RE: Design of Bell & Shaft Drilled Pier Foundation for Pre-Engineered METAL BUILDING