Another pier question

[Skicat]

Is there a guideline for the aspect ratio of a pier? For example, if I have a 30" diamater pier, how long can it be and still be effective? Thank you.

 

[kslee1000]

I don't think there is a "rule of thumb" for pier/pile design. All the dimensions (dia, length) are tied to the soil characteristics and types of loadings.

 

[moe333]

Some of the recommended unit end bearing values for piers (particulary those presented in the ensoft program "Shaft") are based on a minimum embeddment of 10 pier diameters. So for shorter embeddments, you would need to recalc.

 

[Bluefoot]

There is a fact sheet from an early (01 July 1997) publication by USACE (EI 02C097) page 1-12 which consolidated some ratios.

 

[JAE]

The IBC now defines "piles" as elements that have length/diameter ratios larger than 12.

Piers are those with length/diameter ratios of eqaual to or less than 12.

(see chapter 18)

Piles use skin friction primarily.

Piers use end bearing and/or skin friction.

 

[DRC1]

Although many piles that terminate in soil are refered to as friction piles, they often depend on bearing for a significant portion of the load.