Hammer Eficiency and Heave Effect

[massagung]

All,
pls help,

1. what formula to calculation the best diesel hammer can i use for piling regarding weight of ram.
if the design critera are as below :
Spun Pile Diameter 600 mm, Thickness 10 mm, Ultimate Axial Load 200 tons,

where i can read the literatur about this? so i can figure it.

2.what formula to calculation heave effect, since i worry about heave due to near with existing building.

thanks,

M.A.

 

[SlideRuleEra]

M.A. - There will be many hammers that can successfully drive the piling. Doubt that you will find a formula to select the "best". This is because there are so many factors that affect hammer selection. These include things that you have not mentioned such as soil properties, estimated pile embedment, pile weight, and the type diesel hammer (single acting or double acting).

In general terms, you want to use a hammer with a "heavy" ram traveling a small distance rather than a hammer with a "light" ram traveling a long distance; even though both hammers may develop the same energy. This is to keep the velocity of ram as it hits the pile at a minimum. What is "heavy" and what is "light" for a particular pile is a judgment call based on the above variables (and more), not something that can be calculated.

Heave is another possible problem that I doubt can be calculated with accuracy. Also, if the piling are near enough to an existing building for heave to be considered, then better take a look at potential damage from vibration, too.

In summary, pile driving is as much "Art" as it is "Science". IMHO, the best way to answer your questions is to drive a small number to test piles to determine equipment needed and if heave, etc. will be a problem. And as a suggestion, let the pile driver (contractor) propose what equipment to use for the tests.

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[massagung]

thanks for input slideruleera,

pile embedment is about 16 m, and for soil properties ; 0-8 m soft clay, 8-12 clayey silt, 12-18 silty sand, and 18-30 m silt v.stiff to sand, (depth of boring 30m). available hammer diesel single acting and hydrolic, weight of ram available 4-8 ton,.. could you give me reference book related this?



M.A.

 

[SlideRuleEra]

M.A. - There are plenty of books on DESIGN of driven pile foundations. Google on words like "pile foundation design book" and you will find quite a selection.

There are plenty of books ABOUT pile driving equipment, here is one:

http://www.wbdg.org/ccb/ARMYCOE/COETI/ARCHIVES/ti818_03.pdf

What I don't think you will find is a meaningful book, paper, magazine article, or mathematical formula on HOW to select the exact, best piece of equipment for certain conditions. I have been looking for such a book (that is out of copyright) for many years to make available on my website. Have found nothing worthwhile. There are some that "claim" to cover that subject. One is "Pile Driving Guide", by Floyd & Irving Cleveland, published in 1963. I have a copy... I assure you, it is of no value for your purposes.

I'll repeat my earlier recommendation: drive test piling to determine which equipment is suitable.

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