Driving piles near a retaining wall

[Okiryu]

Hi, are any good references for stresses exerted to walls due to pile driving? I will have a new wall (3-5 meters high) and a building about 3 meters apart from the wall. Piles will be approx. 10 meters long. We will be pre-drilling deeper to the depth of the wall foundations, then drive the piles. Perhaps stresses against the wall are minimal as the piles are pre-drilled and also driving is likely to start at deeper locations than the wall foundation. Under these conditions, do you consider vibration against the wall for the wall design?....Thanks for your input... !!

 

[MotorCity]

You are 3m from the wall, but don't forget about the toe and heel. Any reason for not using a single method of installing the piles? Could be less costly since it would require less equipment, mobilization, etc. Since you are drilling a portion of the pile, I assume you are not concerned about the open pile holes undermining the wall foundation, correct? What failure mode of the wall are you most concerned with, considering the effects of vibration from pile driving?

 

[SlideRuleEra]

I don't believe there will be a problem, unless MotorCity's concerns about the toe and heel are a problem. Consider that vibrating compaction equipment could be used on backfill that is 3 meters from the wall. Since predrilling will be performed, I assume displacement piles (wood or concrete) are being used. If steel H-pile are an option, there is likely less concern.

The type hammer and its specs are important, too. A modern hydraulic hammer may be a better choice than a traditional compressed air or diesel single or double acting model. I've attached a paper on successful H-pile driving (with a hydraulic hammer) near (within 1.4 meters) of a specific type retaining wall (4.6 meters high).

http://www.SlideRuleEra.net

http://www.VacuumTubeEra.net

 

[Okiryu]

I do not expect that predrilling holes will compromise the stability of the wall. The piles will be about 300~350 mm diameter. I was more concern about vibration during pile driving can create excessive movement of the wall. SRE thanks for the paper. I will take a look at it.

 

[BigH]

What kind of material are you "pre-drilling" through and then driving?? If it is loose sands, you might find that the vibrations are such that it may cause settlements to occur due to dynamic compaction on the way down - this might influence the footings. Have you thought of auger piles? Might be better (and quieter) than driven piles.

 

[Okiryu]

BigH, materials that will be pre-drilled will be fine grained soils (mostly silts). Some backfill material for the retaining wall may also be pre-drilled. In any case, we do/will not have loose sands in our project site. Auger piles can be an option, but they are expensive here. Civil layout plans are still under preparation, so I will know the exact distance between the building and the retaining wall in a couple of days. I will take a look also at the preliminary toe and heel dimensions as MotorCity pointed out. Thanks for your input.