Pile Capacity from a Excavator Driven Hydraulic Hammer
Pile Capacity from a Excavator Driven Hydraulic Hammer
(OP)
I am trying to determine / calculate the capacity of a pile that is being installed with a hydraulic hammer attached to an excavator. The hydraulic hammer has
a manufactures power rating of 3577 Joules operating at 320 to 600 hammer blows per min. the operator is pushing down on the hydraulic hammer with all the added weight of the excavator (i.e. the tracks are in the air). The pile is being penetrated at a rate of about 40 to 50 mm per min.
Any Thoughts?
a manufactures power rating of 3577 Joules operating at 320 to 600 hammer blows per min. the operator is pushing down on the hydraulic hammer with all the added weight of the excavator (i.e. the tracks are in the air). The pile is being penetrated at a rate of about 40 to 50 mm per min.
Any Thoughts?





RE: Pile Capacity from a Excavator Driven Hydraulic Hammer
RE: Pile Capacity from a Excavator Driven Hydraulic Hammer
mmartens what type of pile are you installing? What depth are you driving to?
RE: Pile Capacity from a Excavator Driven Hydraulic Hammer
It is a hydauliclly driven vibratory hammer on an excavtor. The piles are just 6 inch pipe pile with a pointed end. The depth is about 4 meters to 6 meters or longer if needed the material is mainly clay to a soft sand stone or some times just clay or hard sand. I am looking for a capacity of 10 kN to 40 kN depending on the pile. I am wondering if the capacity can be calculated using hydauliclly driven vibratory hammer mounted on the excavtor. The reason that we use this (the excavtor)is for quick site construction with only about 10 to 20 piles needed in remote locations.
RE: Pile Capacity from a Excavator Driven Hydraulic Hammer
RE: Pile Capacity from a Excavator Driven Hydraulic Hammer
Why has the pipe got a pointed end. I think with the vibro you will have more success driving the open pipe. Just now your pile penetration of 40-50mm per minute is extremely slow and I doubt it is doing your backhoe any good.
RE: Pile Capacity from a Excavator Driven Hydraulic Hammer
The pile is very small in diameter. It is probably pointed for easier driving and tip protection. Do the piles have to be filled with concrete or grout after they are driven?
You could also drive the piles with a small impact air hammer. You could stick the piles with the vibro, then drive them to capacity with a small impact hammer hung from a small crane. You could even "guestimate" the pile capacity using a dynamic pile driving formula, if that is acceptable to the designer.
RE: Pile Capacity from a Excavator Driven Hydraulic Hammer
The pile penetration at first is very fast and them slows to 40-50mm per minute and then even slower but never really stop.
I am thinking if I know (estimate) the excavator load on hydauliclly driven vibratory hammer, knowing the spec. of the hammer and knowing the pile penetration for time. I should be able to estimate the capacity of a pile.
I do not know the equation for estimating "guestimating" the capacity using a dynamic pile driving formula.
RE: Pile Capacity from a Excavator Driven Hydraulic Hammer
if you are stuck with the vibro and are not planning a change to an impact hammer then as far as I know there is no pile driving formula.
The piles are being used as underground pipe supports - does this mean that the piles are spread out over a large area? This means the soils will change and piling to length is not reliable.
Assuming the 2 statements above are correct then I think you should follow PEinc's advice on load testing using the backhoe.
RE: Pile Capacity from a Excavator Driven Hydraulic Hammer
RE: Pile Capacity from a Excavator Driven Hydraulic Hammer
RE: Pile Capacity from a Excavator Driven Hydraulic Hammer
RE: Pile Capacity from a Excavator Driven Hydraulic Hammer
People can talk about the inaccuracy of the driving formulas but remember, up until recent years, that's how pile capacity was determined, in addition to using static load tests.