Turbine Foundation - Bored Pile?

[sykimm]

Hi,

I've seen that almost turbine foundation has been supported using bored pile, not concrete spun pile.

If you know the reason why, please let me know. What are the restrictions to use concrete spun driven pile for heavey vibratory equipment foundations.

 

[SlideRuleEra]

We have used both, drilled piers and driven piling, on two units at the same site (units were designed & constructed 10 years apart).

Drilled piers can be constructed in larger sizes and each one can do the work of several driven piling. This often gives drilled piers a cost advantage over driven piling.

A tuned turbine-generator pedestal, to control vibration, can be designed using either drilled piers or driven piling.

http://www.SlideRuleEra.net

 

[sykimm]

Thanks for your reply.
On your reply, only economic reason would be considered.

How about the pile size-bearing capacity-lateral capacity on each case.

Waiting your reply.......

 

[SlideRuleEra]

That is where a detailed geotechnical program comes in. The results of soil borings, field & lab tests, pile / drilled pier load tests, etc. are essential. For large units, I suggest allowing 2 or 3 months (or more) to collect and analyze the geotech data before making a decision.

http://www.SlideRuleEra.net

 

[sykimm]

Is there any reason to choose the bored pile against lateral loading, such as seismic load?

 

[DRC1]

I am not a big fan of concrete spin piles. The method was developed as a very economical way to make concrete pipe. Someomne then got the bright idea to use it as a foundation element. The problem is that there is a lot of variability in the thickness and concrete strength. If you are concerned about lateral load, I would consider other pile types.
All pile types have their pluses and minuses. Certianly a drilled shaft will accept lateral load, but so will many pile types.

The best pile choice depends on many factors
Site conditions:
overhead clearance
accesibility
neighbors &work hours
underground utilities
Geotechnical:
Soil type
Soil strength
Obstructions
Depth to rock
Liquifaction potential
Other Considerations
Design life
static or Dynamic loads
This is not a complete list, but does show that one can not make a statement that foundation element X is better than type Y. A whole host of project specific factors should be considered before chosing a pile type

 

[BigInch]

For high lateral loadings on driven piles, use lines of battered piles around the exterior of the fdtn cap.

BigInch-born in the trenches.

http://virtualpipeline.spaces.msn.com