IBC 1810.3.13 requirement

[BAGW]

Hi,

I am working on a drilled pier foundation in SDC C. Section of IBC 1810.3.13 states the individual drilled pier needs to be interconnected with ties when in SDC C.

My question is
1) Do we need to connect every drilled pier supporting the column with a tie? Is there any way around this other than stated in section 1810.3.13?
2) Has anyone tried using slabs to restrain the drilled pier? Are there any resources which explains detailing and analysis for this?
3) Does this apply to Auger cast piles aswell? When there are two piles connected with pile cap?

Thanks

 

[r13]

In my opinion, pile cap satisfies IBC requirement, but I wouldn't count on S.O.G. unless stiffened as required by analysis and design. From your understanding, what is the difference between "drilled pier" and "auger cast pier"?

 

[BAGW]

My understanding is both are cast-in place deep foundation with different technique

"When you say pile cap satisfies IBC requiremnet", what do you mean? Which section are you referring to?

 

[r13]

No specific section, nor word. Pile cap "ties" piles/piers together to form group action.

 

[JLNJ]

I'm guessing the OP has single drilled piers, maybe quite a distance apart, and is looking for a way to get around the interconnecting ties. If your golumn grid is wide, the ties are very expensive and penal.

 

[BAGW]

Please see the image below. The way I am interpreting the section is all piles needs to be attached together in the entire building footprint area irrespective of whether I have (2) piles with cap or a single pile.

 

[r13]

I think you are correct. See this linked thread. Link

[ADD]The only thing I'm not completely with is the way to make the grid. One way is as show on your sketch - tie the pile caps, the other way is tie the columns (RC columns, or pedestal for steel columns). I use the latter method most of the time.