PILE DRIVING BASICS -- A GREAT PLACE TO START!

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thread256-110287

WOW! IAM SO HAPPY I FOUND THIS THREAD! YES OLD BUT THE INFORMATION (MANUALS, NAMES & TERMINOLOGY) DISPLAYED WITHIN THIS THREAD SEEMS TO ME TO BE A GREAT PLACE FOR ME TO START AS A BEGINNER DRIVEN PILE DESIGNER AND A 1992 GRAD OF MECHANICAL ENGINEERING UofALBERTA CANADA WHO HAS BEEN WORKING IN THE CIVIL FIELD FOR THE PAST 16YRS (DESIGNING CONCRETE FOUNDATIONS AND LARGER SHOPS MAINLY AND NOW, DUE TO REQUEST OF CLIENTS, IN A REMOTE(ISH) AREA, IAM TO ENGINEER DRIVIN PILES...

READING THIS THREAD, IAM SURE, HAS POINTED ME IN THE EXACT RIGHT DIRECTION...

SO IN ADDITION TO 'MARKING' THIS THREAD (BY CREATING A POST-LOL) THE PURPOSE OF THIS WRITING IS TO EXPRESS MY SINCERE GRATITUDE TO THE FORCES*1 THAT HAVE IT HERE FOR ME; AND OF COURSE TO MARK IT FOR ANY OTHER "BEGINNING DRIVIN PILE DESIGNERS ..

SO => THANK YOU!

OneLove!
OverBles

BillKaz, P.Eng., Father of Emmanouil

footnotes:
*1 THE WRITERS IN THE THREAD ALONG WITH ENG-TIPS FOR HOSTING IT

 

[EireChch]

Some great recommendations from some very experienced engineers. This site was a great find for me a few years ago when i first started working as a geotech. I love discussing all things geotech and have definitely learned a lot.

(on a side note....loose the CAPITALS!!! )

 

[jasonpc]

I am new to pile driving and had a bridge project with a soil profile of 53' of very soft silty clay followed by layers of sandy clay with progressively higher SPT count, but nothing dense for all 100' of the boring. Geotechnical report recommended 84' long 16-inch PPC piles with 136 ton required nominal resistance when pre-boring at the abutments.

Since this was a small off-system bridge, this state doesn't require a WEAP analysis and has a table of open-ended diesel hammer energy ratings as allowable depending on required resistance. In hindsight we should have ran an analysis. The contractor used an ICE I-36 hammer running at the lowest fuel setting.

We had two PDA piles. Both drove initially with very low blow count, less than 12 per foot. One ran some 15 or so feet. The first pile was restruck 24 hours later and only had about 15 blows in 8 inches. The PDA showed a resistance not too far from what we needed so we waited 7 days for another restrike. The first pile met required resistance, but the second pile which ran still didn't. A pile load test was performed on it which showed no problem.

The contractor switched to a smaller hammer which was incidental to our recommendations (old hammer was a rental and they had just purchased the other), a Pileco D30-32.

The very next pile driven in the same bent as the second PDA pile got 56 blows per foot on initial drive with the new hammer on the lowest fuel setting. Which was very close to the required BPF when a WEAP analysis on the new hammer was run.

However, it's been a mixed bag as we continued in the project. Some piles ran during initial drive and others had very low blow count that never increased as you reached toe elevation. But all have set up tremendously after 2-5 days, going from 4 BPF to 4 BPI in 24 hours. In this type of soil it just takes time for friction to set up. Both static and pda analysis showed about 85% of pile capacity is due to friction.